It is the code that connects cryptomus. <script id="cryptomus_popup" src="https://shopify.cryptomus.com/shopify.min.js" data-api-key="**********"></script>

So what should I do?

Is this normal? How do I enable it?

You can charge fees in other ways, create a product called handling fee and create an independent collection for it. Then use this Checkbox APP to display it as a checkbox on the product page.https://apps.shopify.com/onetickFinally, use the following...