To activate your Commerce product, Administrators should navigate to the Product Activation tab on the sidebar navigation  in Customer Portal and select Commerce.

Liferay Version 7.3 - 7.4

For Commerce on Liferay Versions 7.3 -7.4, your Commerce Activation Page will display the following chart giving you instructions on how to activate your Commerce Product. 

Liferay Version 7.1 - 7.2

For Commerce on Liferay Versions 7.1 -7.2, you can download pre-generated licenses for each subscription term.  If you have multiple subscription terms active, you’ll be able to select and download a license for each one.