I have a callout in salesforce which is used to call the other systems to get the data or send data through continuous integration butthe problem here is when coming to test class i am getting only 61percent of coverage since its not covering the methods used in callout because i use only one method in the trigger handler its covering fine 

Here is the callout code --

public class ZuoraBillingAccountTriggerHandler {
    
  
    // SF-2177
    public static void QueueRetrieveZuoraAccountSoldToInfoQueuedJob() {
        // if another job is already queued don't do anything, otherwise queue another job
        List<AsyncApexJob> jobList = [SELECT Id, Status, ApexClass.Name FROM AsyncApexJob WHERE ApexClass.Name = 'RetrieveZuoraAccountSoldToInfoQueuedJob' AND (Status = 'Holding' OR Status = 'Queued' OR Status = 'Preparing' OR Status = 'Processing') LIMIT 1];
        if (jobList.isEmpty() && !Test.isRunningTest()) {
            System.enqueueJob(new RetrieveZuoraAccountSoldToInfoQueuedJob.QueueableOne());
        }
    }


    // SF-2177
    public static void ModifyNeedToUpdateSoldToContactCheckboxesAndQueueJob(List<Zuora__CustomerAccount__c> newList, Map<Id, Zuora__CustomerAccount__c> oldMap) {

        Boolean queueTheJob = False;

        for (Zuora__CustomerAccount__c newZCA : newList) {
            Zuora__CustomerAccount__c oldZCA = oldMap.get(newZCA.Id);
            
            // CSP-878 if Amount_Past_Due__c changed, set "queue Job" to false  
            if(oldZCA != null && newZCA.Amount_Past_Due__c != oldZCA.Amount_Past_Due__c){

            }
            // if checkbox was selected and is being unchecked, don't do anything; otherwise, check the box and set the "queue job" flag to true
            // also, due to the high number of updates occurring as part of the UpdateZuoraAccountCBSSQueuedJob, DO NOT select the checkbox under that circumstance
            else if (oldZCA != null && !oldZCA.NeedToUpdateSoldToContact__c && !newZCA.NeedToUpdateSoldToContact__c && (newZCA.CBSS_Name__c == oldZCA.CBSS_Name__c && newZCA.CBSS_SalesRepId__c == oldZCA.CBSS_SalesRepId__c)) {
                newZCA.NeedToUpdateSoldToContact__c = True;
                if (!queueTheJob) {
                    queueTheJob = True;
                }
            }
            // also, if the checkbox was already selected set the "queue job" flag to true, just to be safe
            else if (newZCA.NeedToUpdateSoldToContact__c && !queueTheJob) {
                queueTheJob = True;
            }
        }

        if (queueTheJob) {
            QueueRetrieveZuoraAccountSoldToInfoQueuedJob();
        }
    }
    public static void updateZouraFields(List<Zuora__CustomerAccount__c> newList, Map<Id, Zuora__CustomerAccount__c> oldMap) {
     List<Zuora.zObject>  zuoraZObjectList = new List<Zuora.zObject>();
        Set<String> contactIds = new Set<String>();
        Set<String> billingIds = new Set<String>();
     
     for(Zuora__CustomerAccount__c newZCA : newList){
       Zuora__CustomerAccount__c oldZCA = oldMap.get(newZCA.Id);         
            if(oldZCA != null && newZCA.name != oldZCA.name){
                billingIds.add(newZCA.Zuora__Zuora_Id__c);
            }
       if(oldZCA != null && (newZCA.Zuora__BillToWorkPhone__c != oldZCA.Zuora__BillToWorkPhone__c || 
                newZCA.Zuora__BillToName__c != oldZCA.Zuora__BillToName__c ||
                newZCA.Zuora__BillToWorkEmail__c != oldZCA.Zuora__BillToWorkEmail__c ||
                newZCA.Zuora__BillToAddress1__c != oldZCA.Zuora__BillToAddress1__c ||
                newZCA.Zuora__BillToAddress2__c != oldZCA.Zuora__BillToAddress2__c ||
                newZCA.Zuora__BillToCity__c != oldZCA.Zuora__BillToCity__c ||
                newZCA.Zuora__BillToState__c != oldZCA.Zuora__BillToState__c ||
                newZCA.Zuora__BillToPostalCode__c != oldZCA.Zuora__BillToPostalCode__c ||
                newZCA.Zuora__BillToCountry__c != oldZCA.Zuora__BillToCountry__c)){
         /*Zuora.zObject acc = new Zuora.zObject('Contact');
        acc.setValue('Id', newZCA.Zuora__BillToId__c);
        acc.setValue('WorkPhone', String.isNotBlank(newZCA.Zuora__BillToWorkPhone__c) ? newZCA.Zuora__BillToWorkPhone__c : '');
         */    
        contactIds.add(newZCA.Zuora__BillToId__c);  
               //contactIds.add(newZCA.Zuora__SoldToId__c);                    
              
     }   
     
    }
        if(!(System.isFuture() || System.isBatch())){
            if(contactIds.size() > 0){
            ZuoraBillingAccountTriggerHandler.zouraUpdate(contactIds);
            }
            if(billingIds.size() > 0){
                ZuoraBillingAccountTriggerHandler.zouraBillingAccountUpdate(billingIds);
        }
  }
 } 
    @future(callout=true)  
    public static void zouraUpdate(Set<String> contactIds){
        List<Zuora.zObject> zuoraZObjectList = new List<Zuora.zObject>();
        for(Zuora__CustomerAccount__c newZCA : [select id,name,Zuora__BillToWorkPhone__c,Zuora__SoldToId__c,Zuora__Zuora_Id__c,Zuora__BillToId__c,Zuora__BillToName__c,
                                                Zuora__BillToAddress1__c,Zuora__BillToAddress2__c,Zuora__BillToCity__c,Zuora__BillToState__c,Zuora__BillToPostalCode__c,Zuora__BillToCountry__c,
                                                Zuora__BillToWorkEmail__c from Zuora__CustomerAccount__c where Zuora__BillToId__c IN :contactIds] ){
          
                    if (!Test.isRunningTest()) {                                       
                    Zuora.zObject acc = new Zuora.zObject('Contact');                                                       
          acc.setValue('Id', newZCA.Zuora__BillToId__c);
                    List<String> nameSplit = newZCA.Zuora__BillToName__c.split(' ');                                        
                    acc.setValue('FirstName', String.isNotBlank(newZCA.Zuora__BillToName__c) ? newZCA.Zuora__BillToName__c : '');
                    acc.setValue('LastName', String.isNotBlank(newZCA.Zuora__BillToName__c) ? newZCA.Zuora__BillToName__c : '');
                    if(nameSplit.size() == 2){
                        acc.setValue('FirstName', nameSplit[0]);
                        acc.setValue('LastName', nameSplit[1]);
                    }
                    acc.setValue('Address1', String.isNotBlank(newZCA.Zuora__BillToAddress1__c) ? newZCA.Zuora__BillToAddress1__c : '');
                    acc.setValue('Address2', String.isNotBlank(newZCA.Zuora__BillToAddress2__c) ? newZCA.Zuora__BillToAddress2__c : '');
                    acc.setValue('City', String.isNotBlank(newZCA.Zuora__BillToCity__c) ? newZCA.Zuora__BillToCity__c : '');
                    acc.setValue('State', String.isNotBlank(newZCA.Zuora__BillToState__c) ? newZCA.Zuora__BillToState__c : '');
                    acc.setValue('PostalCode', String.isNotBlank(newZCA.Zuora__BillToPostalCode__c) ? newZCA.Zuora__BillToPostalCode__c : '');
                    acc.setValue('Country', String.isNotBlank(newZCA.Zuora__BillToCountry__c) ? newZCA.Zuora__BillToCountry__c : '');
                    acc.setValue('WorkEmail', String.isNotBlank(newZCA.Zuora__BillToWorkEmail__c) ? newZCA.Zuora__BillToWorkEmail__c : '');
          acc.setValue('WorkPhone', String.isNotBlank(newZCA.Zuora__BillToWorkPhone__c) ? newZCA.Zuora__BillToWorkPhone__c : '');
          zuoraZObjectList.add(acc);
    }
                                                }
        /*for(Zuora__CustomerAccount__c newZCA : [select id,name,Zuora__BillToWorkPhone__c,Zuora__SoldToId__c,Zuora__Zuora_Id__c,Zuora__BillToId__c,Zuora__BillToName__c,
                                                Zuora__BillToAddress1__c,Zuora__BillToAddress2__c,Zuora__BillToCity__c,Zuora__BillToState__c,Zuora__BillToPostalCode__c,Zuora__BillToCountry__c,     
                                                Zuora__BillToWorkEmail__c from Zuora__CustomerAccount__c where Zuora__BillToId__c IN :contactIds] ){
            Zuora.zObject acc = new Zuora.zObject('Contact');
            acc.setValue('Id', newZCA.Zuora__SoldToId__c);
            List<String> nameSplit = newZCA.Zuora__BillToName__c.split(' ');                                        
            acc.setValue('FirstName', newZCA.Zuora__BillToName__c);
            acc.setValue('LastName', newZCA.Zuora__BillToName__c);
            if(nameSplit.size() == 2){
        acc.setValue('FirstName', nameSplit[0]);
                acc.setValue('LastName', nameSplit[1]);
            }                                                    
            acc.setValue('Address1', newZCA.Zuora__BillToAddress1__c);
            acc.setValue('Address2', newZCA.Zuora__BillToAddress2__c);
            acc.setValue('City', newZCA.Zuora__BillToCity__c);
            acc.setValue('State', newZCA.Zuora__BillToState__c);
            acc.setValue('PostalCode', newZCA.Zuora__BillToPostalCode__c);
            acc.setValue('Country', newZCA.Zuora__BillToCountry__c);
            acc.setValue('WorkEmail', newZCA.Zuora__BillToWorkEmail__c);            
            acc.setValue('WorkPhone', newZCA.Zuora__BillToWorkPhone__c);
            zuoraZObjectList.add(acc);
        }*/
    Zuora.ZApi zApiInstance = new Zuora.ZApi();
      if (!Test.isRunningTest()) {
      Zuora.zApi.LoginResult loginResult = zApiInstance.zlogin();
    }
      if(!zuoraZObjectList.isEmpty()){
  
          List<Zuora.zApi.SaveResult> results = new List<Zuora.zApi.SaveResult>();
  
          if (!Test.isRunningTest()) {
            // callout method documention is here: https://knowledgecenter.zuora.com/CA_Commerce/E_Development_Resources/B_Order_Builder/D_Programming_with_Order_Builder
            results.addAll(zApiInstance.zupdate(zuoraZObjectList));
          }
      for (Zuora.zApi.SaveResult result : results) {
        if (result.Success){
          // nothing for now
        }else{
          //failure, get the errors
          System.debug('CALLOUT FAILED');
          // TODO: add error logic
          /*Zuora.zObject[] errors = result.errors;
                          for (Zuora.zObject error : errors) {
                              String errorCode = (String)error.getValue('Code');
                              String message = (String)error.getValue('Message');
                              System.debug(errorCode + ' ' + message);
                          }*/
        }
      }                  
    
    }
  }
@future(callout=true)  
    public static void zouraBillingAccountUpdate(Set<String> contactIds){
        List<Zuora.zObject> zuoraZObjectList = new List<Zuora.zObject>();
        for(Zuora__CustomerAccount__c newZCA : [select id,name,Zuora__Zuora_Id__c from Zuora__CustomerAccount__c where Zuora__Zuora_Id__c IN :contactIds] ){
    
            if (!Test.isRunningTest()) {
            Zuora.zObject acc = new Zuora.zObject('Account');
            acc.setValue('Id', newZCA.Zuora__Zuora_Id__c);
            acc.setValue('Name',newZCA.Name);
            zuoraZObjectList.add(acc);
            }
        } 
        Zuora.ZApi zApiInstance = new Zuora.ZApi();
        if (!Test.isRunningTest()) {
            Zuora.zApi.LoginResult loginResult = zApiInstance.zlogin();
        }
        if(!zuoraZObjectList.isEmpty()){
        
                List<Zuora.zApi.SaveResult> results = new List<Zuora.zApi.SaveResult>();
        
                if (!Test.isRunningTest()) {
                    // callout method documention is here: https://knowledgecenter.zuora.com/CA_Commerce/E_Development_Resources/B_Order_Builder/D_Programming_with_Order_Builder
                    results.addAll(zApiInstance.zupdate(zuoraZObjectList));
                }
        for (Zuora.zApi.SaveResult result : results) {
            if (result.Success){
                // nothing for now
            }else{
                //failure, get the errors
                System.debug('CALLOUT FAILED');
                // TODO: add error logic
               /*
                Zuora.zObject[] errors = result.errors;
                        for (Zuora.zObject error : errors) {
                            String errorCode = (String)error.getValue('Code');
                            String message = (String)error.getValue('Message');
                            System.debug(errorCode + ' ' + message);
                        }*/               
    
            }
        }                  
        
        }        
    }
  
}