This article will explain the steps required to create a Google Merchant Channel inside the PIM.
Create Google Merchant Channel
From within the PIM, navigate to the Channels menu by locating the Configuration section on the left hand side, selecting it and scrolling down to Channels.
Once there, click Create Channel in the upper right hand corner.
Name your channel something distinctive and choose GoogleMerchant from the type drop down.
Click Create and then retrieve your Merchant ID and your Credentials. The instructions for this can be found here.
Copy your Google Merchant ID and upload the json file generated from the Google Merchant Center:
You can also map specific Google fields to PIM attributes or options by using these following fields: