If you unpack the file and start the program "uploader", you might get a message because the program does not come from the App Store. See here for more info: https://www.macworld.co.uk/how-to/mac-software/mac-app-unidentified-developer-3669596/

But there is a simple solution: right-click on the program and select "open". Now you also get a message, but this one has the button „open" on it. Sorry for that; Apple isn't always nice to independent developers.

If you have any questions, please feel free to contact me at any time at a157b@....