How to install Microsoft Office 365 with my Product Key?

1

If this is a first time activation of the Microsoft 365 (Office) licence, log into this link and enter your product key to register the Office licence on your Microsoft account.

https://setup.office.com/Home

2

Then, once the Microsoft 365 licence is registered or if you previously registered the licence, that is a digital licence linked to your Microsoft account and you can download and install the Office apps from your Microsoft account on this link without the need for the product key.

https://account.microsoft.com/services/