As with all third-party apps in our store, you can reach out to the developers directly with any support queries you have by using the contact details listed there on the app store page.
Can you tell me a bit more about your business and why adding this fee is important to your business needs?
Don | Social Care @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog