Problem with the C# code example ("SampleCode_CSharp_SDLMTCloud.zip") for automated translation using C# programming

Hello, Support,

I have a problem with the C# code example ("SampleCode_CSharp_SDLMTCloud.zip") for automated translation using C# programming.

Source:
<https://languageweaver.exavault.com/share/view/1x830-awnyfmm6>

The connection to SDLMTCloud is missing.
The error message is: "At least one error has occurred." (InnerException = {"Error sending the request."})

Manual access via <https://translate.sdl.com/login> works.
I used the same access data in the C# program.

What am I doing wrong?

With kind regards
Oliver