TFS anonymous access

Hi,

I'm blocked and I need your help. I would like to do on PowerBI a POST API request on a TFS server which works fine on Postman but I always the same issue on PBI:

DataSource.Error: Web.Contents with the Content option is only supported when connecting anonymously.
Details:
DataSourceKind=Web
DataSourcePath=http://{instance}/DefaultCollection/{project}/_apis/wit/

The request is:

let
    url = "http://{instance}/DefaultCollection/{project}/_apis/wit/wiql?api-version=3.0",
    content = "
    {""query"": ""
        SELECT *
        FROM WorkItemLinks 
    	WHERE 
		    ([System.Links.LinkType] = 'System.LinkTypes.Dependency-Forward') 
		    AND Source.[System.WorkItemType] = 'Requirement' 
		    AND Source.[System.State] <> 'Closed'
			
		    AND ( Target.[System.WorkItemType] = 'Task' 
				OR Target.[System.WorkItemType] = 'Bug')
		    AND Target.[System.State] <> 'Closed'
	    ORDER BY [System.Id] 
	    ASOF '1/1/15'    
        mode(maycontain)""
    }",
    Source = Json.Document(Web.Contents(url,[Headers = [#"Content-Type"="application/json"], Content = Text.ToBinary(content) ] ))
in
    Source

As said below, on Postman, it works fine using NTLM Authentication method. So I do not known if the issue coming from the authentication method used on powerbi (basic GET API rest method works) or if the method is not correctly written ...