You need to use ADB to install it which isn't 100% user friendly. I think you only need to root if you want to re-map the buttons to work with ALreader.
I got all the info I needed from
https://forum.xda-developers.com/noo...ght-3-t3698608. It's not very straightforward and it took me awhile to piece all the info I needed together to get the reader to work how I wanted.
The apps I installed are RelaunchX, Solid Explorer, ALreader, and ColorDict.
If you want to try it without rooting you need some kind of back button. I recommend using Button Savior (non root). With root I remapped one of the page turn buttons to be a back button.