How do I include a product on my invoice that must not reflect in my sales (Marine Park Entrance fee

AdyvdP

I need to bill /invoice my customers for a Marine Park Fee that must not reflect in my sales revenue, as this is paid over direct to the National Marine Park fee.
I don't want to issue 1 Wave invoice and 1 hand-written "Marine Park Fee" invoice if possible.
Does anyone know if it's possible to have a "product" that can be invoiced to a client, but not added to sales / income?