I have tried to search for a solution to this problem, but haven't been able to find anyone, so maybe it's not possible.

My current application is a node.js with an Angular2 frontend, where I would like to use nodeBB as a place where registrered user can discuss different topics. It's imporant that no guest is allowed to see anything. I have member registration in my current site, but I can login/register members with OAuth with this plugin:
https://github.com/julianlam/nodebb-plugin-sso-oauth

I have sat all categories to private, and sat the registration type to: "No registration".

So far so good.

I have an existing website where I have a topbar, footer and a left sidebar:

I would like to show nodeBB in the main content area, as I understand this should be possible from the Extend Widgets menu, where I can define a custom header, footer and sidebar. The only problem is that, I have nodeBB to run on a different domain, is it possible to have nodeBB to run directly in my current node.js application?

I know this is probably not possible, but I had to ask :).

Is the road I have taken the right one, or is there a better way so solve my problems?

I really like this awesome forum tool!!