To make a test call, select Settings and more
next to your profile picture at the top of Teams
Choose Devices
Choose Make a test call under Audio devices.
In a test call, you'll see how your mic, speaker, and camera are working. Follow the instructions from Test Call Bot and record a short message. The message will play back for you. After that, you'll get a summary of the test call, and you can go to your device settings to make changes.