The Following Steps Will Help You Import Product Rating Feed To Your Google Shopping Ads
Step 1: Login to Google Merchant Center
Step 2: Click on Product Reviews tab found on the left navigation bar
Note: If you don’t find product reviews, then you need to fill out the Product Rating Interest Form by Google. This will import the ratings from your product page to the Google Merchant Feed.

Step 3: Then click on ‘+’ icon found under Feeds
Step 4: To register a new feed, use the following input
Mode: Standard
Type: Product Reviews
Feed Name: TargetBay.com
Click Continue
Step 5: Choose the input method by choosing Scheduled Fetch and click Continue
Step 6: Set up the feed with the following information
File Name: pubkey-###########.xml (should be the filename of File URL)
Fetch Frequency: Daily
Fetch time: 12:00 AM
File URL: Give the qualified URL to access your file.( For example – ftp://www.mydomain.com/data/products.txt)
If the file is protected with username and password, please define them, else you can leave the following two options empty.
User Name: If user name is required to login to the file URL, then key in the User Name
Password: If a password is required to login to the file URL, then key in the Password
Step 7: Click Save to complete the process.