Data from web - DataSource.Error - unable to retrieve contents of page - powerbi

Question

I'm trying to get a table from a webpage, but I cannot seem to get PowerBI to correctly load that page.
The url is https://www.argentorshop.be/verkoop-uw-edelmetaal-aan-argentorshop/verkoop-uw-goudstaven-en-of-gouden-munten-aan-argentor/
The table I'm trying to import is the GOLD KOERSEN table, highlighted in yellow in this screenshot.
However, after entering the url, I get
Followed by DataSource.Error
We were unable to retrieve the contents of the web page.
I already tried adding HTTP request headers and Command timeout but nothing seems to work.
I also tried to first use a different (working) webpage, and modify the url in the Source step
Source = Web.BrowserContents("https://www.w3schools.com/html/html_tables.asp")
changed to
Source = Web.BrowserContents("https://www.argentorshop.be/verkoop-uw-edelmetaal-aan-argentorshop/verkoop-uw-goudstaven-en-of-gouden-munten-aan-argentor/")
but it yields the same error.
Also, trying to wait for a specific Selector in the options of Web.BrowserContents(url,options) by using [WaitFor = [Selector = "#verkopen > div.bootstrap-table"]] doesn't do the trick.
Does anyone know of a way to correctly import that table in PowerBI?

Answer 1

Try this.
let
Source = Web.Contents(
"http://www.argentorshop.be/nl/graphql",
[
Headers=[
#"Method"="POST",
#"Content-Type"="application/json"
],
Content=Text.ToBinary("{""query"": ""{sellMetalsGrid (metals: [GOLD]){products {entity_id,name,purchasing_price,buying_premium,spread_percentage,spread_currency,selling_premium,price,image,short_description,product_type,fine_metal_content,metal,url,stock_status}}}""}")
]
),
#"JSON" = Json.Document(Source),
data = JSON[data],
sellMetalsGrid = data[sellMetalsGrid],
products = sellMetalsGrid[products],
#"Converted to Table" = Table.FromList(products, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
#"Expanded Column1" = Table.ExpandRecordColumn(#"Converted to Table", "Column1", {"entity_id", "name", "purchasing_price", "buying_premium", "spread_percentage", "spread_currency", "selling_premium", "price", "image", "short_description", "product_type", "fine_metal_content", "metal", "url", "stock_status"}, {"Column1.entity_id", "Column1.name", "Column1.purchasing_price", "Column1.buying_premium", "Column1.spread_percentage", "Column1.spread_currency", "Column1.selling_premium", "Column1.price", "Column1.image", "Column1.short_description", "Column1.product_type", "Column1.fine_metal_content", "Column1.metal", "Column1.url", "Column1.stock_status"})
in
#"Expanded Column1"