C # – Web ASP.NET X ASP.NET MVC Web Forms Authentication Project

I have an "existing" project in ASP web forms .NET.

It turns out that I am developing a new zone for this domain in ASP.NET MVC and I plan to deploy the user control with Action Filters – Authorize.

The user will already be connected to the site and will go to this new area.

How can I perform the authentication check? by API or direct link?