Updated: Nov 20, 2020
While in the game, open the Settings menu and select the "Strava" menu option. You will be presented with Strava's "Log In" screen.
In this case, you are signing into Strava's website with your Strava credentials and the OrbRider application never actually has to handle your password.
Once you authenticate with Strava, their website returns an "authorization" code which is used by the OrbRider server to obtain additional authority from Strava. In this case you have only authorized OrbRider to post activities on your behalf.
It may take a few seconds after you sign in. Once the process is complete you will see some new information including your name and Strava user icon: this indicates the process completed successfully.
If you click the "Deauthorize" button, it will sign you out of Strava and take you back to the Log In screen. This also sends a command to the OrbRider server to delete any access tokens from the key vault, that are associated with your Strava account.
Once you close the settings menu, a new Strava activity will be shown in your active quests log along with a new menu which provides a button that you can click on and submit your activity to Strava when you are finished with your ride.