Hi,

I am trying to call a Static method from Custom Button but getting the error " missing ) after argument List. Can somebody guide me how I can recitfy the same 

Here is my Apex code :
global class ProductGroupFamilyAddOrderTarget {
    
    webservice static void addOrderTarget(){
        List<Sales_Target__c> newSalesTarget = new List<Sales_Target__c>();
        
        List<Product_Group__c> productGrpFamilywithSeries =[SELECT Id,Name,Short_Name__c,
                                                            (SELECT Id,Parent__c,Short_Name__c FROM Children_Groups__r WHERE Group_Level__c='Series' AND isActive__c = True ) 
                                                            FROM Product_Group__c WHERE Group_Level__c='Family'AND isActive__c = True];
        
        SFDC_Fiscal_Year__c currentFiscalYear = [SELECT Id,Name FROM SFDC_Fiscal_Year__c WHERE Current__c= true];
        List<Region__c> region = [SELECT Id FROM Region__c WHERE Is_Active__c = true AND isRegion__c = true];
        List<Sales_Target__c> existOrderTarget =[SELECT Id,Product_Group__c,Region__c,SFDC_Fiscal_Year__c FROM Sales_Target__c WHERE Region__c IN :region AND SFDC_Fiscal_Year__c =: currentFiscalYear.Id];
        Map<String,Id> TargetOrder = new Map<String,Id>();
        if(existOrderTarget !=null && !existOrderTarget.isEmpty()){
            for(Sales_Target__c st : existOrderTarget){
                TargetOrder.put(String.valueOf(st.Product_Group__c)+String.valueOf(st.Region__c),st.Id);
            }
            
        }
        System.debug('Is there any Target Group Created by Error '+TargetOrder.values());
        if(productGrpFamilywithSeries != null && !productGrpFamilywithSeries.isEmpty()){
            for(Product_Group__c prdGrp : productGrpFamilywithSeries){
                if(prdGrp.Children_Groups__r !=null && !prdGrp.Children_Groups__r.isEmpty()){
                    for(Product_Group__c prdGrpChild : prdGrp.Children_Groups__r){
                        if(region !=null && !region.isEmpty()){
                            for(Region__c r : region){
                                if(!TargetOrder.containsKey(String.valueOf(prdGrpChild.id)+String.valueOf(r.Id))){
                                    Sales_Target__c newOrderTarget = new Sales_Target__c();
                                    newOrderTarget.Name = 'Newtarget2020';
                                    newOrderTarget.Target_Type__c ='Product Group';
                                    newOrderTarget.Product_Group__c = prdGrpChild.Id;
                                    newOrderTarget.Region__c = r.Id;
                                    newOrderTarget.SFDC_Fiscal_Year__c = currentFiscalYear.Id;
                                    newSalesTarget.add(newOrderTarget);
                                }
                            }
                        }
                    }
                }
            }
        }
        
        if(newSalesTarget !=null && !newSalesTarget.isEmpty()) insert newSalesTarget;
    }
    
}


And My Custom Button 

{!REQUIRESCRIPT("/soap/ajax/47.0/connection.js")}{!REQUIRESCRIPT("/soap/ajax/47.0/apex.js")}

var result = sforce.apex.execute("ProductGroupFamilyAddOrderTarget","addOrderTarget",{});
alert(result);