Right click the Microsoft Teams icon in your dock, then click Quit.
Open Finder, then click Go and select Go to Folder…
Copy and paste the following into the Go to Folder box, then click Go:~/Library/Application Support/MicrosoftCopy
Right click the Teams folder, then click Move to Trash.
Using Spotlight Search (accessed by clicking the magnifying glass on the macOS menu bar), enter “Keychain” and select Keychain Access. Within Keychain, search for “Microsoft Teams” to find the Microsoft Teams Identities Cache entry. Right (two finger) click this item and select the delete option, then close the Keychain Access app.