9. Settings

On the top right of the Teams window, beside the Minimize button ( - ) you will either see your initials or a picture you have uploaded.
Click on this, and then click on the Settings option.
This will bring up the Settings Menu.

The main sections that pertain to the Phone system are Devices and Calls.

Under Devices you can change your Speaker and Microphone that will be used for calls.

Under calls you can manage how you will deal with incoming calls, and missed calls.