Outcall: she travels, you stay put
Outcall is the only arrangement here: the therapist travels to the room you already hold, and no visitor is ever given an address to come to.
Outcall answers a single question before it can be asked, which is who does the travelling. The answer never changes. She leaves from wherever she happens to be, makes her way to the address written into the thread, and knocks on it. You stay in the room you already have a key for, behind a door you already know how to lock.
No address exists for a guest to travel towards
The house keeps no rooms of its own anywhere. There is no studio, no flat held for the purpose, no street number a guest could be handed. That absence is deliberate rather than a gap somebody forgot to fill. Walking across a city you do not know, looking for a door you have never seen, is where an evening is likeliest to come apart, and outcall removes that stretch altogether.
One clock for the city, another for the airport
Central Amsterdam runs on one figure: forty to sixty minutes from the moment the hour is agreed in writing until she is at your door, the same in every central district. Schiphol and the hotels attached to it are arranged on their own, and the journey time each way is agreed with you before anything else is fixed. Nothing outside Amsterdam and those airport hotels is reached at all.
What it asks of you
Almost nothing, and all of it fits in one message. A full address with a floor and a room or apartment number. A phone left face up and charged, because a phone nobody answers is the one thing that can undo a settled booking. A line about the entrance if the building locks its street door or wants a card in the lift after a certain hour. The booking page lists what a first message should carry, and no part of the figure changes because she had to cross the city to reach you.