I want to recieve the user email using Google Actions as documented here but docs talks about EMAIL permission, but when I read the permission docs here I can\'t find any EM
Ya, unfortunately the Assistant's SDK doesn't give you the email address. But if you implement account linking (like Ahmed mentioned) and use the Streamlined Flows, then you'll be getting the email provided to you; you just need to use the jsonwebtoken library and you can decode the assertion JWT and grab the email address.
That being said, this happens during "sign in" and token exchange... not during the actual action fulfillment. You'll need to issue a refresh token / access token :S