hi Attia, From what you're looking for there may be an option to configure woocommerce booking so that when someone has purchased a product they are placed onto a group membership (woocommerce plugin ) that allows them to buy further items. Which I would suggest you create a package using https://woocommerce.com/products/woocommerce-bookings/ which allows you to book these slots.

So the way it would work is that: The customer registers on your wordpress site and purchase a package which provides them10 consultations.

The membership/subscription package then moves them to a group for 10 consultation based on the purchase of that package, then when they book their consultation you can then move them to a 9 consultation group, and so on until you then downgrade them to not have access to the woocommerce booking to book your consultants.

With that membership/group setting it will allow you to segragate your users to see how many consultations are left and present them different prices if needed to renew packages, etc...

Only quickest way to do it without coding.