Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello, subscription shouldn't require key, just your Microsoft account itself is license.
Please go to https://www.office.com
Sign into the Microsoft account you used for the subscription. Click on Apps on the left.
Then on the upper right, click on "Install apps". This will now download the installer file. Once downloaded, click on the file to install. It will install the Desktop version of the apps for you then.