First of all you need to connect a WordPress site with the ADMIN solution and subscribe to the Premium plan in the Subscription page for the connected site. After that you will see the API key in the Site Configurations, that you need to copy.
Go back to your WordPress backend and select the Automated Export tab in Settings of FPD and paste the API key.
Now you can set the options what kind of file should be exported and who is gone to receive the file. When using WooCommerce and you select "Customer" as recipient, the customer will get the print-ready file when the order is completed/paid.