I assume you’ve already read this article, but if not, give it a look:
Aside from giving us your website’s URL, can you take a screenshot of your htdocs folder to see what is supposed to be there?
Do you have more than one domains? If so, click the arrow for some additional information.
If the domain you’re trying to upload files for is not the domain you signed up with, you should upload the files to the your-domain/htdocs directory and not the default htdocs one.