The KB article is correct.
However : if you go back and look at the article again, you'll see that up at the top of the screen it says "United Kingdom" - indeed, there's even a little Union Jack showing next to it. The 'about' screen in your screenshot, however, says "U.S. Edition".
The KB article isn't referring to the same piece of software that your accountant is running. The software sold as "Sage 50" in the U.S. is entirely separate and distinct from the software sold as "Sage 50" in the UK, so the information in the article is not going to be relevant.
I'd like to be able to offer some further advice, but I've never seen the U.S. software (I'm in the UK), so I'm entirely ignorant as to how one might go about importing data into it. You might like to raise the question in the appropriate section of Sage's Community Hub : https://communityhub.sage.com/us/sage50_us/