Before you can start your stream you will be prompted to select your streaming devices. This you can do in the dropdown selectors on the first page of the application:
You must select and confirm the devices each time when attempting to stream. After clicking the "go online" button, you will be prompted to create a face picture proving your identity as the owner of the account. Additionally, you will need to make sure that each participant that is with your during your current show is selected and is within the frame: