option for manual booking inquiry

I'd like to offer my customers the option to request appointments for certain services. So that there's no initial capacity whatsoever and no payment option either, just the option to make a request for the desired timeslot. bookings are pending by default and if i agree to the request, customers get send the paying-link.

Currently, i don't see an option for that. Sure, i can set "Default Appointment Status" to "Pending", but that will affect all services, which i don't want. I just want to set this up for specific services. And also, even that would mean customers would pay upfront before getting approval, which i don't want either.

So, please you can include this option down the road or maybe there's a workaround you can tell me about? That would be really helpful! Thank you very much.