You don’t need a webcam or microphone to take part. When you join the event, your camera and microphone will be automatically turned off.
For a select number of events, if you’re able to use a camera and microphone, the host may ask you to share your webcam and audio during the Q&A session. They will only do this if you give them permission to do so.
On most devices you can share your audio by clicking the ‘Join Audio’ button on the event screen.