Without knowing what Hosting.com is telling you it is hard to say if the instructions are right or not. They don't seem to provide any doco without a login so I can't look it over.
That said, it is probably safe to assume that their own instructions are what you need to follow on their system . . .
What worked for me is detailed up the first page of this thread starting in post #8412. The shorthand for menu navigation that I am used to:
Virtualmin->Server Configuration->Manage SSL Certificate->Signing RequestSimply means you start on the Virtualmin screen, click on Server Configuration, click on Manage SSL Certificate, etc. If your host is giving you just Webmin (and not Virtualmin) then your path is obviously going to differ. Perhaps you could cut and paste a portion of it here and we could take a look?
The Hosting.com people also mention their
Delightful Support. Have you tried them?