Hi,@ant0nk .
I assume you have logged in without an error. A 404 error in execution output means one of the following:
The paragraph of the cell could not be found in the notebook. Would you check if the same cell's status bar shows a ⚠️ sign (at the bottom right) when you type something in it?
The notebook doesn't exist on the server side. In this case, the extension would have prompted you to specify the path to upload the notebook when you opened it. You may close the notebook and reopen it to trigger the prompt again if you have missed it.
Let me know if this helps solving you problem, or the issue will be closed in 6 days.
Opened notebook, conneted to server but when I try to run any cell I see "AxiosError: Request failed with status code 404" message.