Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hello Amy,
Welcome to Microsoft Community and thank you for posting your query.
Let me assist you with Office 365 error.
The error 771 could be resolved by setting the date and time on your tab.
You may refer the following link which discusses about the similar issue and check if it helps.
I hope the above information helps. Let us know if you need further assistance.
Thank you.