1. In the Microsoft 365 admin center, go to "Billing" and then "Your products" page:
Microsoft 365 admin center / Your Products
2. On the Products tab, in the Software section, select the software that you want to download.
3. On the subscription's details page, in the "Downloads and keys" section, choose the Product version, the Language, and the CPU & file type, then select "Download".
4. To download the key when required, select "Copy key" (to clipboard). Paste the key in a text file or a note app in a secure location and enter it as instructed during the software installation. The key is needed to activate the downloaded software.