You can create a dropdown additional option to your services to let customers select if they prefer a female or male therapist.
First availableThe dropdown additional option can be used together with the option to let customers select the first available therapist. If customers select that they prefer a female therapist and also the first available, the system will only assign female therapists to the booking.
In the Choices section of the additional option, you can create choices, for example, a choice for no preference, male or female therapist.
In the Resources tab of each choice, you can set that the choice can be provided only by some of your resources.