Refresh the page
At the top of the browser, near the address bar, there should be a “refresh” symbol. Depending on your browser it may be in a different location, but it is generally in the top left corner. Click this, and your page will refresh.
Check the audio jack port
Look at your audio jack port
Make sure your headset cable isn't loose and plugged in all the way
If the cable is plugged in all the way, unplug the cable and plug it back in.
Check the headset mute button
On your headset look for a Mute Button
Make sure that button is not enabled on the headset
Check the correct microphone source is selected
Click the three vertical dots next to the Screen Share icon in Juno Live Session
Select your headset or microphone from the Choose Audio Source drop down list