The Jazz Theory Book - Mark Levine
Improvising Jazz - Jerry Coker
Jazz Theory Handbook - Peter Spitzer
You need to learn some basics like decoding Standard Notation onto your ukulele fretboard to a basic level to get the most out of these books.
Also they are based on having access to a piano keyboard, so you need to work out how to use your ukulele fretboard instead of a piano.
Also they do not have any complete tunes, just fragments to illustrate the lessons. You have to find the recordings they refer to if you want complete versions. Then you have to work out how to use the recording to work out how to play the melody or progression or both on your ukulele.
The books require some intellectual activity to be of use to ukulele players. They are not spoon feeding easy play arrangements to ukulele players.
But they are available on Kindle, which you can load onto your device. So instead of playing social media computer games all day, you can turn off the data to your device and just leave the voice and text on, and then open Kindle and read the Jazz Books. These are books which you read many times and then use them for reference, so you may not ever get tired of them. Maybe you would turn the data on for a moment to find and download a tune to study, then you can turn it off again. If you are on a bus or train you can work out the stuff in your head and work it on your ukulele when you get back to your ukulele.
Another thing you can consider doing is reading more widely. The book: "On The Road" by Jack Kerouac (also on Kindle), was written about the era of Be-Bop style Jazz, according to some. If you read this book, you may pick up some of the atmosphere of the times and terminology and if you read the analysis of the people in the book etc. you may get a better feel for the life and times of Be-Bop genre of Jazz. Or you may get offended by the Maleness of the book, whichever, you will get some more ideas on the atmosphere of the music you want to study. There are similar books and biographies you can find and read which are about the atmosphere of the times when the music was created. These books make great interludes when your hands are worn out from playing or you hit a plateau or whatever.