Letting customers pay the credit card fees is currently unavailable, adadamandsons1. We can create an item and add it to the transaction instead.
Follow the steps below to make an item and pass these charges to your customers through invoices:
Go to Sales on the left panel, then select Products & services.
Click the New icon, then choose Service.
Enter a Name for easy identification. (Example: Credit Card Fees).
Pick the account you'd use to track the processing fees under the Income account.
Click Save and Close.
Once done, add the CC Fees to the customer's invoice to include this in the calculation along with the other goods or services. I've added a screenshot below for reference:
@adamandsons1 Bear in mind that the above is simply your next best option; it will never fully recapture the costs of your credit card fees, given that the added line will itself be subject to credit card fees.
As to why, although it is generally allowed, it remains illegal in certain states. I expect Intuit simply doesn't want to poke that hornet's nest, so leaves it up to the users to fend for themselves.