To make sure you don't run into any browser permission camera and microphone issues, you can set Chrome's camera and microphone access to "Always". Here's how to do this:
Open Chrome
At the top right, click More > Settings.
Click Privacy and security > Site settings > View permissions and data stored across sites.
Here, search for Lessonspace (and/or room.sh) and set Allow for both Camera and Microphone.
This way, the next time you join a Space, your settings will automatically enable the camera and microphone.