How to access user email in a Zoom App

Zoom Apps Configuration
Vanilla JS

Is there a way to access current user’s email in a Zoom App?
I tried using /users/me API → Zoom Meeting API, but apparently it requires access token using Authorization Code grant type, but I don’t want to redirect user to that Zoom authorization page to get authorization code.

And Client Credentials grant type is giving {"code":200,"message":"Invalid api key or secret."}