Practitioners add the tip when they take payment at the visit. If they take none, the client gets one email offering to tip instead. Either way the tip goes to the practitioner in full — your studio percentage is only ever taken from the visit price.
Prerequisites
When a practitioner presses "Take payment" at the end of a home visit, the same tip percentages you set below appear as buttons on their screen. The client tells them the tip, they tap it, and it goes on the same card charge as the visit — one payment, one line on the client's statement.
When a practitioner presses "Check out" and no tip was collected, the client is emailed once, offering to add one. There is no reminder and no second email. Nothing is sent if a tip was already taken at the visit, if the visit was referred back at intake, or if the practitioner never checked out — so nobody is ever asked twice for the same visit.
Go to Appointments → Appointment Types. The panel headed "Tips after a home visit" sits above your list of services. It applies to every travel visit service you offer, not one at a time.
Type up to four whole percentages (they start at 15, 18 and 20) and click Save. The client sees these as buttons, each showing the actual dollar amount it works out to for their visit — so a 20% button on a $140 visit reads "$28.00". The percentage is only a suggestion; what gets stored and paid is the dollar amount.
The checkbox "Let clients enter their own amount" adds a free-text box next to the buttons. Untick it and clients can only choose one of your presets — the server refuses anything else, so it holds even if someone tries to work around the page.
Choose "No tipping". No email goes out after check-out, and the tip page stops accepting payments — including from a link somebody saved earlier. Nothing else about the visit changes.