3CX on Android - Need help

Has anyone installed 3CX on Android?
If yes, I need help. I have entered all the details correctly but the app does not register. Can someone please tell me what would I be doing wrong?

Hi

Has is registered before with 3cx?

perhaps you want to try a different network as it could be your isp

Please make sure to enable only G711 codec

Here is a screenshot of the settings as well