Service charges and fees, such as an automatic gratuity on a large party or a delivery fee, are applied the same way discounts are.
The charge appears as a line on the ticket and the totals adjust.
Tap the charge line in the ticket panel, then tap the remove option shown.
Admin Portal, Service Charges/Fees Screen. That is also where you set whether a charge is taxable and whether it counts toward tip out calculations, which is the detail that most often needs checking when a payroll number looks wrong.
Source: Global Payments Genius POS User Guide. Newly built article, pending review.