Pull Data from Rest API -Appointment Plus

[Anonymous]

Dear Power BI Community,

I am looking for help with pulling in data from a Rest API. The system is called Appointment-Plus. Here is the API documentation:  https://s24400.pcdn.co/wp-content/uploads/2019/04/TechnicalGuide.pdf

So in researching/watching videos I know I need to pull it from the web connector in Power BI. The https link I am using is "https://ws.appointment-plus.com/Appointments/GetAppointments" After that is what I am struggling with. Can anyone help with how to pull in their API? 

I am a little out of my depth and don't fully understand how API's work and haven't used one in BI before.

[Anonymous]

Sorry for the late response, only seen it now. 
I don't have an api_key to test but this should get you close (paste it in Advanced Editor as a New Query)

let

   api_key= "your_api_key",

   fxGetAppointments = () =>
     let
         base_url = "https://ws.appointment-plus.com/Appointments/GetAppointments",
         accessToken = "Bearer " & api_key,
         options = [Headers = [Authorization = accessToken, response_type = "json"]],
         source = Web.Contents(base_url, options),
         jsonList = Json.Document(source)
    in
         jsonList

in
   fxGetAppointments