Within Settings > My Business, click [Manage] against the shop followed by [+ Add Another Barber/Therapist]:

Firstly, enter their name as shown to customers:

Secondly, assign the staff member their services. You can select services from existing staff members and adjust these as needed:

You can also add new services specifically for this staff member using the + New button:

If adding a new service, remember to save with the green tick button.

All service attributes can be further edited later within Settings > My Business. If the list is correct, click [Proceed] to finish assigning.

Then, set their default working hours. Click on a day if it needs changing and edit the availability:

You can then optionally issue them an admin login, as well as add their photo to display during customer booking - both can be done later if needed:

Once you click [Finish], they will appear within Settings > My Business where you can further configure their settings and services.