New Sennheiser PC8 headset for Skype - the microphone is said not to work. What to do?

I have a Lenovo laptop with Win10 and a headset for Skype. Sennheiser PC8. When I do the echo test for video-audio testing, the mic is not accepted. In the settings (Bluetooth and other devices) the Sennheiser headset is listed under Audio. There or with Skype and in the settings I find nothing that helps me. Skype only recommends connecting another microphone and / or updating the audio drivers. Shouldn't the latter work automatically? If not, how do I do it exactly?

Try Audacity.

https://www.audacity.de/downloads/

Then you can try to test your microphone there.

Thank you - but do I have to download Audacity first? Or is there a test function on the website. So see ad hoc no button or anything.

No, download it. Is also very practical.