There are easy fixes and hard fixes for problems.
The best place to go for a fix to any problem is internet, of course, and especially YouTube.
Still, sometimes the recommended solutions are extremely complex, so that you need to look at a bunch of solutions before extracting a good one. You need to pick and choose the best solution.
One situation which needs a simple solution is the ability to read most eBooks on Kindle, especially epub formatted books. Epub. is, in fact, the format for most ebooks, but not Kindle books.*
Kindle uses a proprietary computer ebook format derived from an older .mobi format, whereas most ebooks are in that different format, .epub. The Kindle format is called .azw. .azw is added to the computer name of the book as a suffix, xyz.azw.
If you look for ways to convert .epub to .azw Kindle format, you will find a number of complex approaches to it, whereas a simple one came up just the other day.
That new approach is simply to download the .epub version and rename the .epub suffix with the .png suffix. A book called xyz.epub becomes xyz.png.
Then all you do is send that book by email to your special “email to Kindle address as an attachment. Voila.
So always look for the simplest solution.
*Ebooks come in different technical digital “formats”, identified with a suffix to the computer name for the book. So a book called xyz becomes xyz.epub, or xyz.mobi, or xyz.pdf, etc. .epub or .mobi or .pdf is the suffix.