Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Microsoft 365 web version is free.
You simply access via the web browser by visiting https://www.office.com.
Sign into your Microsoft account, then click on the 9-dot icon on the upper left to access Apps.
Files you want to work on must be uploaded to OneDrive in order for you to open with the web apps.