Connect React Native app to existing ASP.Net Identity

I have an existing website, which is build using ASP.Net MVC using ASP.Net Identity to manage the users and permissions.

I would really like to create an app which is able to log into the same identity so they can share the same information across both platforms.

Is this possible, I have done multiple google searches and not come up with anything or anyone trying to do a similar thing?

Any help would be appreciated to point me in the direction of a tutorial perhaps of how I could achieve this.