If I need more than one provider for a service, I can't map the service with simplybook.me. The function is simple and missing in your system. Please implement it by all means. Other system can represent this.
As an example, to change a tire you need two mechanics. The customer books the service tire change and for this two specific free mechanics must be bookable. Only if both are available, the appointment can be booked.
Activity
If I need more than one provider for a service, I can't map the service with simplybook.me. The function is simple and missing in your system. Please implement it by all means. Other system can represent this.
As an example, to change a tire you need two mechanics. The customer books the service tire change and for this two specific free mechanics must be bookable. Only if both are available, the appointment can be booked.