I have diffiiculty writing test class for this class. My test class is not covering any line, Please Help.


public class NSSyncCommanUtility {
    public static void SyncDataWithNetSuite(List<Sobject> lstSobject, String SobjectAPIName){
        String JSONBody = prepareJSON(lstSobject, SobjectAPIName);
        if(String.isBlank(JSONBody) || String.isEmpty(JSONBody)) return;
        System.debug('==========jsonBody======='+jsonBody);
        makeCallout(JSONBody, SobjectAPIName);
    }
    
    @future (callout = true)
    Public static void makeCallout(String JSONBody, String sObjectName){
        NetSuiteCredentials__c objNetSuiteCredentials = NetSuiteCredentials__c.getValues(sObjectName);
        if(objNetSuiteCredentials == null) return;
        String nlauth_account = objNetSuiteCredentials.Nlauth_Account__c;
        String nlauth_email = objNetSuiteCredentials.UserName__c;
        String nlauth_signature = objNetSuiteCredentials.Password__c;
        String nlauth_role = objNetSuiteCredentials.Nlauth_Role__c;
        String nlauth_url = objNetSuiteCredentials.End_Point_URL__c;
        if(String.isBlank(nlauth_account) || String.isBlank(nlauth_email) || String.isBlank(nlauth_signature) || String.isBlank(nlauth_role) || String.isBlank(nlauth_url)) return;
        HttpRequest req = new HttpRequest();
        Http http = new Http();
        req.setHeader('Authorization', 'NLAuth nlauth_account='+nlauth_account+',nlauth_email='+nlauth_email+',nlauth_signature='+nlauth_signature+',nlauth_role='+nlauth_role);
        req.setHeader('Content-Type','application/json');
        req.setMethod('POST');
        req.setEndpoint(nlauth_url);
        req.setBody(JSONBody);
        req.setTimeout(120000 );
        try {
            HttpResponse res = http.send(req);
            System.debug('======res.getBody()===='+res.getBody());
            if(res.getStatusCode() == 200){
            
                
            }
        } catch(System.CalloutException e) {
            System.debug('========e======='+e);
        }
    }
    }