This article explains how to configure your device settings before you join a meeting.
Step 1: Click on the "Computer audio" section. If you wish to change the Mic and Speaker setting click the settings section, this can be down by the arrow below.
Step 2: Below you can change the input and outputs for the speakers and microphone. To do this simply click on the appropriate dropdown and choose the device you wish to use from the list. Providing the device is plugged in and working normally It will automatically show on the drop-down lists.