See attached for Polycom quick reference guide and user guides.

Using your Polycom CX300 with Microsoft Teams

If your organization is fully using Teams, here's a few things to know about CX300 functionality.

What still works:

The answer button, mute button, and volume buttons will still work as expected on the handset.

The LCD screen on your Polycom phone will say a message about "Office Communicator" and that is totally normal and expected behavior.
You'll want to also make sure your Polycom is set as your default Audio device in Teams (guide here).
The redial button will no longer dial the last number dialed.
To dial out, you won't be able to use the physical key pad on the CX300. Instead, to make an outbound call, you will need to use the dial pad within the Teams app either on your computer or your mobile device. See this Microsoft guide for more information on how to call a phone number from Teams >>
- NOTE: In the Desktop app, the dial pad will not show up if your Teams window width is half the screen or less.