One Signal Push notification not working after publishingt he app on play store

Hello coders,
I made a School app Named SARK Connect and used oneSignal push notification and it was fine working but after publishing the same app on play store when I send any notification oneSignal shows status as Delivered but It don’t reaches on any phone.

Even when I install the app manually by downloading from modular it works fine.
But not with playstore downloaded apps.

I am very worried about it.

And I couldn’t send any screenshot because I am confused which screenshot I should send
Because there is no error in my compiled app
The problem is only with playstore app.

So.

My app. : My app On Play Store