Hello, thanks for your message
If your newly downloaded Kindle files don’t show up under the Kindle tab, please go to Settings >> Kindle >> Click Set to the Default Path >> OK, then your Kindle books will show up.
If there is still the same problem, please feel free to contact us via support@epubor.com.
Best regards,
Epubor Team

It's been over a year since I last used ePubor Ultimate, but now I'm having trouble locating where my Kindle downloads, including KU, are located on my Mac.
I've looked here:
/Users/<username>Library/Application Support/Kindle/My Kindle Content
/Users/<username>/Library/Containers/Kindle/Data/Documents
This was recommended on the Apple Community forum but there was no such destination
/Users/<username>/Library/Containers/com.amazon.Kindle/Data/Library/Application Support/Kindle/My Kindle Content/
Searching with DDG doesn't reveal anything new.
Searching using Find Any File doesn't come up with current content.
Any information that leads to my current Amazon downloads would be greatly appreciated.
Thank you,
Tod
2019 27" iMac running macOS Ventura 13.2
Amazon Kindle version 6.85.2