Credentials have been cleared.

Test an API requestSubmit an API request and see a formatted JSON response. Go through the authorization flow if there are no stored credentials for the user.
Test the auth flow directlyGo directly to the authorization flow. If there are stored credentials, you still might not be prompted to reauthorize the application.
Revoke current credentialsRevoke the access token associated with the current user session. After revoking credentials, if you go to the test page, you should see an invalid_grant error.
Clear Flask session credentialsClear the access token currently stored in the user session. After clearing the token, if you test the API request again, you should go back to the auth flow.