In some cases app may fail to add its code to your templates automatically (due to custom theme structure, or some 3rd party apps installed). In this case we'll need to add app code to your Product template manually.
Please grant our support team access to your Store admin (Themes section), so we may check and make sure app is working properly. You may send invitation to firstname.lastname@example.org. Please also drop us a line and explain what exactly is wrong.