Hi,
Firstly, I would recommend removing the authorization token from your post - especially if it is a real one.
Secondly to get the email the api: /wiki/rest/api/user/email
is correct. However, you need to request specific permission for you app to use this API: Guidelines for requesting access to email address.
It is also still possible for a user to hide their email adress, even if your app has the ACCESS_EMAIL_ADDRESSES scope that is required.
Also note that normally, AP.request is adding the authorization header for you, no need to add that explicitly.
Richard