Advance Server is a special server from Garena EpEp that is provided to try games or games that are under development. Players can report the technical glitches or bugs of the game and also get the rewards like Gun Skins, Free diamonds, title, Outfit, and others.
This app will guide you about:
What is EpEp advance server
Advance server advantages
List of Advance Servers
How to Register
etc
hope it could help you of steps how to join advance server OB