Concatenated string or dynamic query in Power BI Service

Sorry, missed to attach in earlier post.

I am using the below function to call by using the URL of tfs collection and the queryID used in TFS for specific requirement. The same works when i directly use the plain query without all concatenation/variables

"https://<Org>/tfs/<Collection>/_apis/wit/wiql/<QueryID>?api-version=6.0"

function used : 

(WIUrl as text,WIQueryID as text, WICollection as text) as table =>
let
Source = Json.Document(Web.Contents(WIUrl,
[RelativePath=WICollection& "/_apis/wit/wiql/"&(WIQueryID)&"?api-version=6.0"])),
workItems = Source[workItems],
#"Converted to Table" = Table.FromList(workItems, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
#"Expanded Column1" = Table.ExpandRecordColumn(#"Converted to Table", "Column1", {"id", "url"}, {"Column1.id", "Column1.url"})
in
#"Expanded Column1"