Access denied for the controller in Batch Job in D365FO

I have created a batch job with a controller class, contract class and a service class for automatically placing a deferral schedule on hold if it's payment method is 'PIA'. On attaching the w3wp process to the class and debugging the service class it gives an error "Access denied to controller". Let me know what should I do to remove the issue. I am not using a menu item for it. I am using a an AOT query to go through in the service class