Authorization - WSDL File, Proxy class in C# - Visual Studio Desktop App

Hello,

I have received a SOAP application with the SOAP_UI from my customer.
I was able to create a proxy class for C# via a WSDL file. I integrate this into my project and get these errors.
C:\Users\Freitag\source\repos\TEST\SOAP\_WSDL>wsdl /par VUISTADASERVER_WSDL.wsdl

Visual Studio 2017, C# WPF Desktop App

What could be the cause?
How can I solve this?
Can I create a new WSDL file on my own and can I adapt the ContentType? If so, where?

private void btnGet_Order_Queue_Click(object sender, EventArgs e)
{
	using (STADAService dMES = new STADAService()
	{
		Credentials = new NetworkCredential("pds", "pds"),
		PreAuthenticate = true,
		Url = "http://ADDXACDD4:8080/orawsv/PDS/",

		
	}) 
	{
		try
		{

First error is

Error when requesting with HTTP status 401: Unauthorized.

Second error is
The request content type found by the client is 'text/html; charset=iso-8859-1', expected was 'text/xml'.
Error in request with the following error message:

--
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
  <soapenv:Body>
    <soapenv:Fault>
      <faultcode>Server</faultcode>
   </soapenv:Fault>
  </soapenv:Body>
</soapenv:Envelope>
--.

 Inside the wrapper, proxy class, I have this

dMES.RequestEncoding =

I can't set this. Is not available.

      request.Accept = "text/xml";
      request.ContentType = "text/xml";
      request.Headers.Add("Content-Encoding", "utf-8");

How I can change the ContentType and so on.

Is the failure, a wrong WSDL file?

How can I solve it?

Thanks for your help.

Best regards Markus