https://epubor.com/unable-to-convert-ridibooks-to-pdf-with-epubor-ultimate.html
Unable to convert Ridibooks to PDF with Epubor Ultimate
epubor ultimateunableconvertridibookspdf
https://macappstore.org/ridibooks/
Install Ridibooks on Mac OSX - Mac App Store
Jun 13, 2022 - Install Ridibooks on Mac OSX using brew cask
mac osxapp storeinstallridibooks