oneSignal API based remote push notification

Has anyone been able to integrate oneSignal remote push notifications on iOS?
I know there’s pushover, but that requires another app from pushover to be installed first.
The API documentation seems to focus on Xcode, and I would like to use it in Xojo

Yes and… no.

I was able to make it work on a test device by side-loading the app through Xcode.
But I haven’t gone as far as making it work in a production app.

I’m struggling to have the entitlement for Remote Notifications set and get User permission to use them; did you manage to do so and if so, would you be willing to share this?