Refreshing data from REST API

Hi

I have a REST API setup as one of my datasets.  What is the best way to get it to schedule refreshes, say 3x a day like 8am,12pm,3pm to capture the latest data in my report.  

My REST API code is as follows.  Is there a line i should add to the API code or any other way that i can get this to update automatically. 

let    
url = "API LINK HERE", 
body = "{""Username"": ""xxxxxxxx"", ""Password"": ""xxxxxxxx"", ""CustomerID"": ""x""}",   

Source  = Json.Document(Web.Contents(url,   [ 
     Headers = [#"Content-Type"="application/json"],
     Content=Text.ToBinary(body)   
]   
)   
),
in
    #"Renamed Columns1"