How do I install the Bookworm app?

1

I am the teacher in charge of a computer lab with 22 Endless CPUs.

Of the 22 I was able to install the Bookworm ebook reader app directly form the App Store on 17 of them, however I was unable to do the same on 5 computers, since the app was not available in the App store on those copmputers.

What would be the procedure in this case?

2

As of version 3.0 Endless OS has adopted Flatpak, a new application distribution system

3

I tried to use that option and it asked me for a password, I don’t have any
password installed.