In order to join a session, you will first need to make sure the app is downloaded.
Once downloaded, you can click on the Riverside guest invite link that your host has provided. This will open the app and ask for permission to access both your mic and camera. Permissions will need to be granted for both. You can choose to disable your microphone or camera prior to joining the session.
Once you have entered your name, you will be able to join the session!