Azure maps not displaying mapped data points in publish to web when location used

Microsoft Copilot has recommended https://api.postcodes.io as an open source option to geocode from an API.

It's based on open Office for National Statistics (ONS) and Ordnance Survey data, and doesn't require an API key for authentication.

I was able to use the code below as a custom function to lookup the latitude/longitude in a similar way to in that blog post.

(postcode as text) =>
let
 CleanPostcode = Text.Replace(Text.Upper(Text.Trim(postcode)), " ", ""),
 Source =
  Json.Document(
    Web.Contents(
      "https://api.postcodes.io/postcodes/" & CleanPostcode
    )
  ),
Result = Source[result],
Output =
  if Result <> null then
    [
      Latitude = Result[latitude],
      Longitude = Result[longitude]
    ]
  else
    [
      Latitude = null,
      Longitude = null
    ]
in
Output