Quit from Teams (use Teams > Quit, don't just close the window).
In the Finder, open the /Applications/Utilities folder, and then double-click Terminal.
For Classic Teams, enter the following command, and then press Return: rm -r ~/Library/Application\ Support/Microsoft/Teams
For New Teams, enter the following command, and then press Return: rm -rf ~/Library/Group Containers/UBF8T346G9.com.microsoft.teams rm -rf ~/Library/Containers/com.microsoft.teams2