Desktop App fails to Login through OKTA

We have a desktop application that scans to Google Drive. Our customer, a western state, uses OKTA SSO. Our product has worked with several SSO product in the past. This product uses oAuth2 in the Google Drive Login. When the user attempts to login via SSO, he gets his name in and the screen with the blue Allow shows. User presses Allow to allow our product to access Google Drive. But then we see a browser page “hmm cant reach this page” this address is or similar port. Our product hangs at that point. We have no SSO code in the application, since we understand the most apps work with SSO witgout any modification.

Does OKTA have a setting that is required to allow applications to access Drive through OKTA ? Does anyone offer any suggestions?