How to provide access protection for ReactJS application and WP site (users log in)?

Question

JavaScript

Suggest a solution.
There is a site on WP, in essence, it simply produces pages from the ones necessary for the application and restricts users depending on the role in accessing the pages.
Now there is an old application that will be rewritten in react and later launched on a separate node server, but at the first stage it is assumed that we will compile it and attach it to the page in the form of js.
What solutions can be provided to provide access to the application itself exclusively to logged-in users and, depending on the role, without forcing them to enter the password again and protect the data by itself)?