If you are on a mac, this is what you can.
Please use the instruction here: https://support.microsoft.com/office/how-to-remove-office-license-files-on-a-mac-b032c0f6-a431-4dad-83a9-6b727c03b193 Download and run the license removal tool to clear the cached business credential, this should then allow you to sign in using your personal Microsoft account.