Can delete all the notifications

lib/helpers/notifications_helper.dart

@@ -102,4 +102,10 @@ class NotificationsHelper {
         },
       ).exec())
           .isOK;
+
+  /// Delete all unread notifications
+  Future<bool> deleteAllNotifications() async =>
+      (await APIRequest(uri: "notifications/delete_all", needLogin: true)
+              .exec())
+          .isOK;
 }