let
    Source = () => let
        Source = Json.Document(Web.Contents("https://login.microsoftonline.com/"&#"TenantId"&"/oauth2/token", 
        [
            Headers=[Accept="application/json", ContentType="application/x-www-form-urlencoded"],
            Content=Text.ToBinary(
                "grant_type=client_credentials
                &resource=https://api.loganalytics.io
                &client_id="&#"LogAnalyticsPrincipalId"&"
                &client_secret="&#"LogAnalyticsPrincipalSecret"
            )
        ]))[access_token]
    in
        Source
in
    Source