Step 1: create google authorization url with scope
must include https://www.googleapis.com/auth/userinfo.email
Example:
https://accounts.google.com/o/oauth2/v2/auth?scope=https%3A//www.googleapis.com/auth/userinfo.email%20https%3A//www.googleapis.com/auth/drive.file&access_type=offline&include_granted_scopes=true&response_type=code&state=login&redirect_uri=https%3A//yourdomain.com/auth/google&client_id=your_client_id.apps.googleusercontent.com
Step 2: get access_token
Documentation: https://developers.google.com/identity/protocols/oauth2/web-server#httprest_3
Step 3:
Method 1:
https://www.googleapis.com/oauth2/v3/userinfo?access_token=your_access_token
Method 2:
curl -H "Authorization: Bearer your_access_token" https://www.googleapis.com/oauth2/v3/userinfo
Result:
{ "sub": "108378817912896508886", "picture": "https://lh3.googleusercontent.com/a/default-user\u003ds96-c", "email": "youremail@gmail.com", "email_verified": true }