A Lookback session typically captures the screen, audio and camera, but while screen and audio are required=always captured during a Lookback session, capturing the participant's camera is not technically required to be able to start a Lookback session.
Camera recording options. The one who sets up a the round in a project can make camera recording either optional, required or disabled, as shown below.
Communicate expectations. Make it clear in your pre-session communication with the participant what's expected, so they have the right expectation when they enter the set-up process to grant permissions that is the starting point of any session.
Participant side: it's not possible for a participant to turn off the camera in the middle of a session. So, if the researcher has set participant camera to optional in Round settings, the participant needs to toggle camera to 'off', in set-up, before the actual session begins.
Moderator side: the moderator has the choice not to enable camera before joining the session, and can also turn off camera recording during the session.
Participants on iOS devices: Generally speaking, the participant camera can always be captured, however there is an exception that concerns iOS devices. Due to Apple privacy restrictions, Lookback is only allowed to capture participant camera within Participate (Lookback's app for mobile devices). As soon as the participant on an iOS device leaves Participate (=opens another app, thereby backgrounding Participate) the camera recording is automatically paused. As soon as the participant returns to Participate the camera recording resumes.