Square offers a variety of options for enabling customers to tip through the Square Appointments Point of Sale app (iOS/Android) or Square Online Store.
After enabling these settings, artists can opt to display a separate tipping screen where customers can select a tip after the payment has been processed. Similarly, for online transactions, artists can enable tipping through your Square Online Store. During the checkout process, customers will be prompted to add a tip amount to their order.
When you process the payment through Square, the tip amount will be added to the total transaction amount.