Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
1
If you have redeemed the product key to associate the Office licence on your Microsoft account as a digital licence, log into your Microsoft account on this link (https://account.microsoft.com/services/), and from there, you can download and install Office on your MacBook Air.
2
If the installation is not successful:
Please provide a screenshot of the error you see indicated.
Also, at the top left of your MacBook Air desktop, click the Apple icon and select 'About this Mac', what version of MacOS is installed on your laptop?