Import wix-bookings on the backend returns error

Hello, when I’m trying to use wix-bookings on the backend I’m getting “e rror loading web module backend/http-functions.js: Cannot find module ‘wix-bookings’”.
If this module is not available at the backend how can I get availability for the staff member at the backend.

plese answer this question, how can we get service availability from backend?

Backend code requires the use of the wix-bookings-backend API.