public IActionResult InviteUser(int userGroupId, int userId) { //? maybe there should be some form of invitations/requests to join groups try { _userGroupService.AddInvitation(userId, userGroupId); return(Ok($"Invitation sent to user with Id: {userId}")); } catch (AppException ex) { // return error message if there was an exception return(BadRequest(new { message = ex.Message })); } }