Thanks for reaching out to us. Allow me to help and provide some insights about setting up CC Fee on your customer's transaction.
Currently, Point of Sale (POS) doesn't have a feature to set up CC Fee on your customer's transaction. What you can do is, is create an non-inventory item and leave the price blank. So every time you make sales, you'll have to manually compute the fee that you've collected.
Here's how you can set up an item in the POS:
On your POS window, click the item List.
On the Item Name, type-in CC Fee.
Put a zero amount on the Regular Price and Order Cost option.
On the Tax drop-down arrow, make sure to select the Non-taxable.
On the QuickBooks option, you can map the item on the desired expense account.
If you need further assistance with the steps, I recommend calling our Point of Sale Support. They have the tools to do a remote session and walk you through the process.