data = {
    "firstName":"TestAPI",
    "lastName": "TEST",
    "email": "[email protected]",
    "phone":"+79993332211",
    "date":"September 15, 2021",
    "time":"09:30",
    "endTime":"11:30",
    "datetime":"2021-09-15T09:30:00+0300",
    "price":"95.00",
    "type":"Standard",
    "appointmentTypeID":20215494,
    "duration": "120",
    "calendar": "Refyne ",
    "calendarID": 4887339,
    "location": "TEST",
    "notes": "TESTTESTTEST",
    "forms":[{"id": 1655981,
                "name": "Appointment Form",
                "values":
                  [
                      {"id": 1673900822,
                       "fieldID": 9149417,
                       "value": "Address 1231 street 12",
                       "name": "Address"
                        },
                        {
                            "id":1673900823,
                            "fieldID":9149418,
                            "value":"TEST",
                            "name":"Do you have any allergies?"
                        },
                        {
                            "id":1673900824,
                            "fieldID":9149419,
                            "value":"TEST",
                            "name":"Special Requests"
                        },
                        {
                            "id":1673900825,
                            "fieldID":9149420,
                            "value":"TEST",
                            "name":"How did you find out about us?"
                        },
                    ]
            }
        ]

}

headers = {'Content-type': 'application/json'}
url = "https://acuityscheduling.com/api/v1/appointments"
res = requests.post(url, json=data, auth=(UserID, APIKey), headers=headers)
print(res.text)