Sharing Player Information Between Games

So, basically what I’m trying to do is make a game where players can view all of their information from every game I’ve made under the name Sphere Studio. Basically like the xbox app.

I want them to have their avatar (not roblox avatar), achievements, and game progress all available at a whim. I’m assuming that I need to use api or make a website for them to log into and everything syncs through that.

If I’m right that I need to use api or a website, what is api and what it the best way to do this?