You don't need a Teams
API token anymore.
Microsoft Teams used to hand out an API token for third-party devices, and MuteDeck could use it. Microsoft has removed that system. MuteDeck controls Teams without it, so there is nothing here for you to set up.
Short version
No token, no setting, no steps. Install MuteDeck, start a Teams meeting, and your controls work. If you want the current setup notes, they live in the Teams setup article.
What used to be here
Teams had a Third-party app API section under Settings → Privacy. You turned it on, generated a token, and MuteDeck picked it up automatically. Teams then told MuteDeck what your meeting was doing, which made state updates quick and exact. This page used to walk through those steps.
What changed
Microsoft removed that system. The setting is gone from Teams, the tokens went with it, and anything built on top of it stopped working. That includes the official Microsoft Teams Stream Deck plugin, which is no longer available.
Why Microsoft retired it is theirs to explain. We only know the practical part: there is no token to generate anymore, so if MuteDeck or a guide ever asked you for one, you can skip it.
How MuteDeck controls Teams now
MuteDeck never leaned on that API alone. It detects and controls Teams through interface discovery, which works without a token and without anything to enable inside Teams. Mute, camera, screen share, and leave all still work, on a global hotkey or on your Stream Deck.
There is one thing worth checking: because MuteDeck reads the Teams interface, your Teams language has to be one it supports. If Teams runs in a language MuteDeck doesn't know yet, it can't read your meeting state. The Teams setup article lists the supported languages and where to switch Teams over.
If your Stream Deck keys stopped working
That is almost certainly the retired plugin rather than anything on your machine. MuteDeck puts the keys back: replacing the Teams Stream Deck plugin covers what happened and how to set it up again.