As a guest, you can set your microphone, audio, and camera settings before a meeting, see section Joining meetings.

You can edit the settings at any time in Swyx Meeting or define them initially as host.

For the list of recommended audio and video devices, see

https://service.swyx.net/hc/en-gb/articles/360004151080-Recommended-Audio-and-Video-Hardware-for-Swyx-Meeting (You must probably be logged in to access the contents).