I can make an Http request, but I’m having a hard time to get info from firebase database. Anyone haves some tips on how to make an integration with Firebase?
If you can make a HTTP request with control of verb, URL, headers, and payload, then you can use the API as documented by Google: REST API 的安装与设置 | Firebase Documentation
It’s important that player clients (and your installer) does not contain any authentication tokens that would give players privileges you don’t want them to have, so you may still want to interpose a separate simple application server, depending on what exactly you want to do – you may also be able to just use the affordances for client/server that Firebase already has built in.
There’s a Firebase plugin on the marketplace, too. I have no idea whether it’s any good, but it might be worth checking out if you want to save some time in putting together the HTTP payloads and leave that to someone else: Firebase - Features in Code Plugins - UE Marketplace