Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello,
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 school credential, this should then allow you to sign in using your personal Microsoft account.
If for any reason it still wouldn't work, tell me your macOS version? and where you purchased the subscription, via Msft or Apple?