The Google Product Listings campaigns are included with every account that has an active platform fee.
As part of the platform fee, you can create as many Product Listing campaigns as you would like! Remember, the platform fee is charged on your account, if you have applicable services - every 30 days.
It is important to remember though, that these are separate from Google's Shopping, Search, Retargeting, and Display campaigns.
Those campaigns require ad spend and must be purchased separately. Additional details on the billing of those types of campaigns can be found here.