protected async Task <bool> SendNotification( User fromUser, int toUserId, UserNotification notification, IUserService userService, [AllowNull] string fcmToken = null ) { if (!Helpers.IsProperString(fcmToken)) { var collaboratorAccount = await userService.GetAccountByUserId(toUserId); if (collaboratorAccount == null) { return(false); } fcmToken = collaboratorAccount.FcmToken; } var fromUserFullname = Helpers.IsProperString(fromUser.PreferredName) ? fromUser.PreferredName : $"{ fromUser.FirstName } { fromUser.LastName }"; if (notification.Message.Contains(TokenNotifierName)) { notification.Message = notification.Message.Replace("", fromUserFullname); } return(await _userNotifier.NotifyUserSingle(fcmToken, notification)); }