Hi - sorry for the late answer on this one
The short answer is - you cant.
The whole point with the grant access page, is that your app users authenticates the access to his data, to your app. The returning token is then the future key the that users data. Your app has the responsibility to save this token along with some user-id, and use this token on all future requests.
The user should not have to grant access to your app every time he uses it.