As an Attendee, by default, you will not have access to share your webcam or microphone. You'll need to be invited to the stage by the Host.
Once the webinar Host invites you to the stage, you, as the Attendee, will be able to activate permissions and access your microphone or webcam.
This is what you will see when the webinar starts if you are on a desktop device:
After the webinar Host invites you to Go On Stage, you will see an invite message and will be able to use your mic or webcam on Demio.
You can now click the Camera or Microphone icon to turn them on at the bottom of the pop-up window and click Go On Stage.
If you are on a mobile device, the options will look very similar:
If your microphone or webcam is still not working, you can Run a System Check here.
You can also shoot an email at [email protected] for more help!