Manually importing demo content files for Clean Portfolio (free) theme

Hello, I'm using the theme Clean Portfolio (free) and having a similar issue to some other users. I activated the Catch Themes Demo Import plugin, but the page says "There are no predefined import files available in this theme. Please upload the import files manually!" Where can I find these files, and how do I upload them properly? After searching on the internet, I found some files here: https://github.com/catchthemes/ct-demo-import/tree/master/import-files/cleanportfolio/free. I tried downloading the .xml file (I couldn't figure out how to download the .dat or .wie files) and uploading it manually: Manual demo files upload > Import Demo Data. After this I got an error message saying that some of the content didn't import properly. Can you help with this? Thanks so much! P.S. I think I'm having the same issue as the user @xchelsey (post #255814, response #255842 from August 2020).