First of all your NGINX config is incorrect. You want to access the forum under /community, but are using /forum in it.
This is a simplified version of my NGINX config:
And here my config.json:
Me and a few other people have made an online game with an online authentication system and want to know if there is any way to use user accounts and their profile pages that have already been created to play the game as profiles to post on a nodebb forum.
To clarify, this is a question about seamlessly replacing the default nodebb registration and user profile system or hooking a replacement - though it would be preferable if features such as groups continued to work after having done so, we are not fussed about the forum fully working so long as users can start topics and use all the normal forum features. It would also be a big plus if it could do things like share sessions, so that you do not have to log in twice. As an example, Bethesda's community pages, which use nodebb, can do this.
I'd be greatful for any pointers or advice the community can give. I know this is quite an advanced question. Thank you!