Hey! I'm just trying to record a fee separately.  Can I record Processing Fee as an other Income via Journal entry?

If I don't want to add a line item in my Invoice.
Actually I have to record a fee separately due to my software limitation. If I've a Invoice of $100 and I push payment $100 and want to push a fee $4.00 separately instead of one payment 104 (payment + Fee)?

Please guide me in the right way.