As an Attendee, by default, you will not have access to your webcam/microphone. You'll need to be invited to the stage by the Host!
Once the webinar Host invited you to the stage, you, as the Attendee, will then need to enable Chrome permissions in order to allow Demio to access your microphone or webcam.
This is what you will see when the webinar starts.
After the webinar Host invites you to Go On Stage, you will see a confirmation message. You will have to option to turn on your webcam and microphone here.
To enable your webcam and microphone, you will need to grant your browser permission. You will see a popup in the top left of their browser. You should click 'Allow.'
You, as the Attendee, will now be able to use your mic or webcam on Demio. You can now go to the bottom and click the Camera or Microphone icon to turn them on.