Uitilizing external user accounts

I have set up an individual user accounts system in a webserver that people can register and login.

How can I use these custom accounts for my multiplayer game?

For example, login from within the game, use the user’s account for some gameplay logic and have my game server check if the user is actually logged in.

Hi, you can use http requests, or use the webrowser widget plugin, or create a webbrowser extension, or use a sql or firebase database to keep track of the login status. Probably many other ways too.