Hi,
Based on my research, following steps for your reference:
Password Reset:
If you have forgotten your password, open the app or go to teamapp.com.
From the app:
Select the Log In or Sign Up button.
Enter your registered Team App e-mail.
Click the 'Forgot your password?' link.
Check e-mail for temporary passcode and enter code to access.
Once logged in, you can update your password via 'settings / change password'.
Note: Make sure the e-mail address is registered with Team App otherwise you will not get a password reset e-mail. Check your 'junk' and 'SPAM' folders.
Or you can try the steps in the following link:
Change your Microsoft account password
Reset or recover your Microsoft account