I am using a class, in this I am using three HttpRequest on different URL for getting the data. 
Now I am creating the test class and for HTTP request I have used HttpCalloutMock but when i am run the test class it threw the error -
12:55:15:828 FATAL_ERROR System.AssertException: Assertion Failed: Expected: http://abcd/donor, Actual: http://xyz/oauth

My code - 
@Istest
public class SyncDonorToGCTest {
    @Istest 
    static void testCallout(){
        
        List<sObject> records = new List<sObject>();
        
        records.add(new Contact(firstname='TestFirstApi',lastname='LastMiddle',Email='TestEmailApi@gmail.com'));
        insert records;
        
        List<Id> ContactId = new List<Id>();
        Contact ContactVal;
        ContactVal = [SELECT Id FROM Contact];
        ContactId.add(ContactVal.Id);
     
        Test.starttest();
        Test.setMock(HttpCalloutMock.class, new SyncDonorCalloutHttpCallout());
        SyncDonorCallout.ContactDataCallout(ContactId);
        System.assertEquals(200, 200);
        Test.StopTest();
    }

}

@Istest 
global class SyncDonorCalloutHttpCallout implements HttpCalloutMock{
    global HTTPResponse respond(HTTPRequest req){
        
        System.assertEquals(Label.NewDonorApi, req.getEndpoint());
        System.assertEquals('POST', req.getMethod());
        
        // Create a fake response
        HttpResponse res = new HttpResponse();
        res.setHeader('Content-Type', 'application/json');
        req.setHeader('Authorization', 'Bearer sfdsdfdfs');
        res.setBody('{"userid":"sffsdf","password":"","first_name":"first_name","last_name":"last_name","email":"email","address1":"address1","address2":"address2","city":"city","state":"state","country":"country","zip":"zip","phone":"phone","date_of_birth":"date_of_birth","phone2":"phone2","suppressConfirmationEmail":"0","sf_api_call":"0"}');
        res.setStatusCode(200);
        return res;
    }
}

Please suggest me what should I do.