Call queues in Microsoft Teams are determined by Distribution Lists. These lists are usually populated by members of a department.
There are numerous reasons why someone may want to opt in or opt out of a call queue. Directions on how to do so are as follows:
In Microsoft Teams, click on the Ellipse menu, then click on Settings
On the left side menu, click on Calls. If you are part of one or more call queues, they will appear at the top of the page, next to your Personal queue.
Toggle Receive calls from this queue to suit your needs. Having the toggle in the 'Off' position means you will not receive calls
In Microsoft Teams, tap on your Profile Icon in the top left corner, then on Settings
Tap on Calling
Scroll down the Call Queues section, then toggle as needed