Download this forge component,

1. Change the Username and Password in the connector module for REST API's service, the Username and Password will be available here under integration in Acuity portal.

2. Few settings needs to be configured in the portal as well. For example, the calendars needs to be set in Acuity portal with the Time Zone based on the appointment type.

3. Based on the requirement, the service action can be used accordingly. For example, to create an appointment, Post_Appointments service can be called.

Note: Acuity is a paid API service.