Execute a SOAP call using New-WebService behind a proxy

New-WebServiceProxyProxy.ps1

Function New-WebServiceProxyProxy {
    [CmdletBinding()]
    Param(
        $proxyURL,
        
        [Parameter(Mandatory=$true)]
        $Uri
    )
    $proxyObject = [System.Net.WebProxy]::new($proxyURL)
    $TempFile = [System.IO.Path]::GetTempFileName() + "_wsdl.xml"

    $WebRequest = Invoke-WebRequest -Uri $Uri -Proxy $proxyURL -UseDefaultCredentials

    $Content = [XML]$webRequest.Content
    $FirstChild = $Content.FirstChild

    if($FirstChild.Name -eq "xml"){
         $null = $Content.RemoveChild($FirstChild) 
    }
    
    $Content.OuterXml | Out-File -FilePath $TempFile
    
    $Hash = @{}
    $Hash.Uri = "file://" + $TempFile

    $webProx = New-WebServiceProxy @Hash
    $webProx.proxy = $proxyObject
    remove-item $TempFile
    return $webProx
}