Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
The error code 0x0 is a known issue for macOS users. See: https://support.microsoft.com/en-us/support/known-issues/unknown-error-0x0-license-not-found-error-microsoft365-macos
To clarify, are you using a Mac or Windows computer? If you are using a Mac, what version of macOS are you using?
Please go to: https://account.microsoft.com/services
Can you confirm if your license or subscription appears there and is listed as active?