Good evening, I'm using the form aleksandar-babic / magento2-GCR (https://github.com/aleksandar-babic/magento2-GCR/commit/d8d5ed1b8b479d05fd2c85e7365a671f3175a2f4) to participate in google customer reviews. I would need to modify Success.php as it uses getSku for gtin but this is not good for me as I use a custom attribute for Ean so I need to change getSku with the custom attribute labeled Ean. I tried to change with getEan () but this gives me an error in the console: Error: Product GTIN format is invalid! (anonymous) @ cb = gapi.loaded_0: 682. Not being an expert programmer I ask you for help.