Thank you for reaching out to the Community! I’m happy to provide some guidance with locating an app that will allow for product customization, to get this resolved. While it’s difficult to definitively confirm what app was being used for the shop above, I recommend looking through the Shopify App Store for similar options. I’ve gone ahead and suggested a few below, you can check out:
Please feel free to contact the app developers directly for any questions regarding functionality or customization abilities, as they will be able to provide further assistance. To contact them, you can head to the Shopify App Store and select Support > Get Support.
Please let me know if you have any other questions!