Steps to get Google Reviews QR code :
Step 1: Go to the Google Place Finder Tool and look up your business in the search box. You can do that here.
Step 2: Copy your businesses “Place ID” from the maps tooltip.
Step 3: Modify the following Reviews URL and past in your “Place ID”: https://search.google.com/local/writereview?placeid=PUT ID HERE
For Eg: https://search.google.com/local/writereview?placeid=ChIJg8DRHwmNOIgRXy1H
Step 4: Select a QR code generator you like. A free QR code generator site you can use is https://www.qrstuff.com/
Step 5: Copy and paste your new Reviews URL into your QR code website and download your QR code.
Step 6: Print and use your QR code to start getting reviews!