[OneSignal] 400 Bad Request

Hi all, I'm developing a mobile application that facilitates booking of resources in an organisation. One of the requirements is that push notifications be sent to a user upon any changes/requests to one of their bookings.

To do this, I've followed the instructions on https://success.outsystems.com/Documentation/Development_FAQs/How_to_Use_Push_Notifications_with_OneSignal to set up and link OneSignal to my Outsystems project, but attempting to send a notification always returns a 400 Bad Request.

The following is my test notification sending logic:



(I've double checked the REST API & App Id)

Plugin is available as I've never gotten "Plugin not available", only "Notification failed to send" due to the exception handler.

I receive the same error when using the similar methods to send a notification to a user based on User ID as well as OneSignal Player ID.

I'm running on Outsystems 11.0, OneSignal 2.0.1, CommonPlugin 3.0.0. These are the only additional dependencies my project has.

OneSignal was only configured for Android (via Firebase) and the Application is currently only intended for supporting Android. Notification sending was working prior but it broke somewhere along development (also 400 Bad Request), as a result I tried to reset OneSignal by removing and re-adding the plugin & API but still face the same errors.

Sending a notification directly from the OneSignal dashboard works (notification will be received).

All registered test users are logged into the application during testing.


Error Logs:

In Error Logs:


In General Logs:
{
  "app_id": "< --removed-- >",
  "included_segments": [
    "All"
  ],
  "contents": {
    "en": "Test Notif"
  },
  "send_after": "01-09-2019 02:25:32",
  "ios_badgeCount": 0,
  "ios_badgeType": ""
}


I'm absolutely stuck trying to solve this and will be very grateful for any assistance.

Thank you!

Yeah, I have the same issue.
Any solutions?