You can see all the APIs here. Just be sure to change the domain from roblox => roproxy as @Exozorcus mentioned.
However there may be other deprecated APIs they haven’t included in there since they also included APIs not being used anymore, so I can give you a brief overview of other ones:
fonts.roblox.com/docs
realtime.roblox.com/docs
captcha.roblox.com/docs
forum.roblox.com/docs
Roproxy does not support these subdomains so I just used these example ones.