One link per business
Copy the booking link shown on Booking Page. It is the OperMae address you are signed into, then /book/, then the handle you choose. Only one handle is active at a time.
Edit it
Open Booking Page. The handle is edited inline next to that address, and saved with the rest of that screen.
Choosing a handle
Use your business name. Lowercase letters, numbers and hyphens work best, and short is easier to say out loud.
Retiring an old link
When you change your handle, the previous address stops working straight away and is not redirected or reissued. Update the places you have shared it before you change it.