publishing error

Welcome aboard...
In the FAQ:
https://musescore.org/en/faq
...are many questions.

The image you previously attached reads:
"MuseScore.com returned an error code: 401 Authorization required."

In my first reply, the link to which I referred:
https://musescore.org/en/faq#faq-359393
...shows an answer to the following question:
"Why do I get the error code 401?"
(Based on your attached image, this seemed to me to be likely related to your predicament.)

You just now wrote:
where on the FAQ is my answer?

Okay, so open this link:
https://musescore.org/en/faq#faq-359393
...and look for the answer near the bottom. (It's the only question shown with an answer.)

Regards.