To set up a Pilates Duet Appointment Type, you can use our different Scheduling Limits for different Appointment Types feature. This will allow two people to schedule a Duet Appointment Type at the same time, while only one person will be able to schedule solo Appointment Types.
Head over to to Business Settings > Availability and select Set different hours for certain appointment types. Select your Duet Appointment Type, then click Save Appointment Type. Click Client Scheduling Limits near the top of the page, change the Appointments Per Time Slot from 1 to a 2, then save your changes.
If you'd like someone to be able to schedule both spots in the Duet session (say someone wants to bring a friend along), you can go to Client's Scheduling Page > Customize Appearance > Scheduling Page Options. Check the box next to Services: Allow Clients to Book Multiple Spots, as seen in the screenshot below. Save your changes and your clients will have the option to book multiple spots for your Duet Appointment Type!