Validating users between 2 different idp

Help
,
1

So, we have our Application(App-A) using Auth0 for Authentication. We have a customer who owns a different application(App-B) which uses a custom IDP or maybe Azure AD. is there a way to integrate these applications in a way that

  1. when a person is logged in and authenticated in the App-B, they have to be automatically authenticated to our App-A . Can I use some kind of an SSO token or any other method for this?

Thanks
ym