Hello LION.Software!

May you please provide us more details about your problems. For examples:

"I tried different settings on OneSignal" which settings did you try?

"but I can't subscribe" - where you did you try to subscribe?

"The layer from OneSignal opens, I allow notifications," - this is possible to do in browser popup at the top and in the middle of page from app.

So waiting your reply, with the best regards, Leonid