Poll userinfo from a RequiredAction?

I’ve got a customer use case where they’d like to poll the userinfo endpoint from the UI of a custom RequiredAction. They’re using it to determine if the user has verified their email by clicking on the link in another device (common when the user gets the verification email on their phone). They want to provide updated feedback to the user in the browser that effectively sends them to the next step (as it would had they clicked on the email verification link on the same device/browser).

However, since this is the middle of a login session, and there has been no token issued to a client application, I don’t know how to call that endpoint. Any ideas?