How to make secure transfer of information from backend to frontend?

Question

Flask

Frontend sends a request with the user login argument , after which backend catches this request and returns information about the user in json format.

As far as I understand, anyone can simply follow the url and a huge json will be returned to him, or make the same request.

How to share information more securely and hide it from others?
It's about user information.

Thank you in advance.

Answer 1

Sessions, cookies.
Flask has the flask_login module, a login_required decorator for every request.
After authorization, a cookie with a session ID is passed to the user and all requests will be authorized for this user.