That's what I did. I unzipped the SZ file and move the SZ app to /Applications. Then, I launched SZ and allowed it to install the extension. If and when I get reply from the developer, I'll post it.

Jon

macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365