Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
The AADSTS500200 error usually comes from a personal Microsoft account being directed to a sign-in page for work or school accounts. If you have multiple types of Microsoft account, conflicts may occur when being redirected.
Log out of all the accounts, then delete all Microsoft cache files and login credentials from your device. Consider restarting your device before signing back in with your personal Microsoft account.