Can someone help me with getting my test class working? What is the test class missing?

Here is my Class:

public class NICCCloneWithArtifactsController 
{
    
    //added an instance varaible for the standard controller
    private ApexPages.StandardController controller {get; set;}
     // add the instance for the variables being passed by id on the url
    private NI_Change_Control__c r {get;set;}
    // set the id of the record that is created -- ONLY USED BY THE TEST CLASS
    public ID newRecordId {get;set;}
    
    // initialize the controller
    public NICCCloneWithArtifactsController(ApexPages.StandardController controller) 
    { 
        // initialize the stanrdard controller
        this.controller = controller;
        // load the current record
        r = (NI_Change_Control__c)controller.getRecord(); 
    }
    
    // method called from the VF's action attribute to clone the Change Request
    public PageReference cloneWithArtifacts() 
    {
        
        // setup the save point for rollback
        Savepoint sp = Database.setSavepoint();
        NI_Change_Control__c newR;
        
        try 
        {
            
            // copy the change request - ONLY INCLUDE THE FIELDS YOU WANT TO CLONE
            r = [select Id, Priority__c, Request_Summary__c, Request_Details__c, Change_Type__c, Date_Required__c, Deployment_Group__c, Data_Change__c,
                  New_Custom_Script__c, Outage_Required__c, Manager_Reviewer__c, Peer_Reviewer__c, Developer_Compiler__c, Related_Servers__c, Related_Hosted_RFC__c, NI_Change_Owner__c 
                  from NI_Change_Control__c where id = :r.id];
            
            newR = r.clone(false);
            // SANDBOX =====================================================================
            //newR.RecordTypeId = '012P00000000G42';      // Full ID = 012P00000000G42IAE
            // PRODUCTION ==================================================================
            newR.RecordTypeId = '0126000000016TJ';        // Full ID = 0126000000016TJAAY                         
            newR.Change_Status__c = 'New';
            newR.Cloned__c = true;
            newR.Cloned_From__c = r.Id;
            newR.Cloned_w_Artifacts__c = true;
            
            insert newR;
            
            // set the id of the new po created for testing
            newRecordId = newR.id;
            
            // LOOP THROUGH ALL RELATED ARTIFACTS 
            for (NICC_Artifact__c artSource : [SELECT Id, Artifact_Name__c, Type__c, Description__c, Document_Link__c, Complete__c FROM NICC_Artifact__c WHERE NI_Change_Control__c = :r.id])
            {
                
                NICC_Artifact__c artNew = artSource.clone(false);
                artNew.NI_Change_Control__c = newR.id;
                
                insert artNew;
                
                List<Attachment> Attachments = new List<Attachment>();
                for (Attachment attach : [SELECT Body, BodyLength, ContentType, Description, Name FROM Attachment WHERE ParentId = :artSource.Id]) 
                {
                     Attachment newAttach = attach.clone(false);
                     newAttach.ParentId = artNew.id;
                     Attachments.add(newAttach);
                }
                
                insert Attachments;             
            
            }

        } 
        catch (Exception e)
        {
            // roll everything back in case of error
            Database.rollback(sp);
            ApexPages.addMessages(e);
            return null;
        }
        
        return new PageReference('/'+newR.id+'/e?retURL=%2F'+newR.id);
        
    }
    
}

Here is my Test Class:

@isTest
private class TestNICCCloneWithArtifactsController 
{
 
    static testMethod void testArtifactCloneController() 
    {
		
        // Creae a Change Request
        NI_Change_Control__c nicc = new NI_Change_Control__c();
        //SANDBOX ====================== nicc.RecordTypeId = '012P00000000G42';
        //nicc.RecordTypeId = '012P00000000G42';
       // PRODUCTION =================== nicc.RecordTypeId = '0126000000016TJ';
        nicc.RecordTypeId = '0126000000016TJ';
        nicc.Change_Steps__c = 'test';
        nicc.Date_Required__c = system.today();
        nicc.Request_Summary__c = 'Test';
        insert nicc;
 
        // create new Artifact record
        NICC_Artifact__c ar = new NICC_Artifact__c();
        ar.NI_Change_Control__c = nicc.Id;
        ar.Type__c = 'Customer Sign-off';
        ar.Document_Link__c = 'TEST';
        ar.Description__c = 'TEST';
        insert ar;

        // create an Attachment for the Artifact
        Attachment a = [Select Body from Attachment Limit 1];
        Attachment attach = new Attachment();
        //attach.BodyLength = 10;
        attach.Name = 'test.txt';
        attach.ParentId = ar.Id;
        attach.Body = a.Body;
        insert attach;                           
         
    }
 
}

 Here's the page code:

<apex:page standardController="NI_Change_Control__c"
     extensions="NICCCloneWithArtifactsController"
     action="{!cloneWithArtifacts}">
     <apex:pageMessages />
</apex:page>

 Any tips would be greatly appreciated!