public ActionResult <SubscriptionDTO> GetById(int id)
 {
     try
     {
         SubscriptionDTO subscription = subscriptionsService.GetById(id);
         if (subscription == null)
         {
             return(NotFound($"Subscription with id {id} not found."));
         }
         return(Ok(subscription));
     }
     catch (Exception exc)
     {
         return(StatusCode(StatusCodes.Status500InternalServerError,
                           $"Something went wrong: {exc.Message}"));
     }
 }