Web alerts reading during IRL

Hi there. I'd like to start IRL streams my setup is phone camera streamed via vdo.ninja to obs on my pc and I have second phone with chat, but I have completly no idea how to get voice alerts from donations readed via phone speaker.

As you can guess it's web overlay, I tried just open it in my phone browser, it works but only when browser with that tab open is on the top, I tried chrome and firefox, tried unrrstricting battery usage and permit run over other apps but without success.

I need to have alerts running in background and even with screen turned off all the time, is there a way to do that?