I have not been able to get the offline mode working since it was supposed have been introduced in October. There simply is no “make available offline” on any book I have opened for reading, not even that “Hugo”-book mentioned in another recent thread.
Have tried this with a browser on my computer as well as on a Android mobile device (S9+)
It was from that case I took the book as an example to try to “make available offline”… Totally different, as I do not have that option on my PCOS-computer… (windows 10). The options is missing, this is in Firefox (latest), Chrome (probably latest), Edge Dev (latest), and in Real New Edge (Chromium based).
It might also be that I am looking at the wrong place for that option, but others seem to find it…
And as I just posted, it is now available in all browsers except Firefox, which is my primary web browser (ESR, latest release, 68.4.2 on a newly reinstalled computer, on others I use ESR 52.9.0 which is compatible with older plugins)