Invoke-WebRequest -Uri "http://127.0.0.1:6060/onvif/device_service" `
  -Method Post `
  -Headers @{ "Content-Type" = "application/soap+xml" } `
  -Body '<?xml version="1.0" encoding="utf-8"?>
<s:Envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope">
  <s:Body>
    <tds:GetCapabilities xmlns:tds="http://www.onvif.org/ver10/device/wsdl"/>
  </s:Body>
</s:Envelope>'