Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hello,
Do not post your product key here. We are all users on this public forum and sharing that is a security risk.
The error in your screenshot mentions a Multiple Activation Key which is strictly for Corporate Volume Licensing. These are typically managed by IT administrators for organizations and are not standard retail keys for personal use.
Where exactly did you purchase this copy of Office 2024 LTSC? Was it directly from Microsoft or a major authorized retailer, or was it from a website selling keys at a heavy discount?