I appreciate you joining the thread. Let me share additional information about the feature availability concern.
 

I understand that the option to charge your clients for an online processing fee when making a purchase is beneficial to you and your business. However, we're unable to give a specific time frame as to when this would be available in QuickBooks Online.

Additionally, please keep in mind that our developers will be based on the number of requests they received from customers like you. The more request they will get, the more likely it'll be implemented in the future. Your patience will be highly appreciated.

Moreover, if you have submitted feedback, you can visit our QuickBooks Online Feature Requests website to track the status.
 

Please don't hesitate to come back if you have any other concerns or suggestions. I'm always here to help you. Stay safe!