Pretty sure Amazon kindle doesn't use epub. Many years ago there was software that could convert their format to epub but would be very unsurprised if that is no longer possible.
Discussion
Calibre
Amazon uses a couple that are easily convertible any which way with Calibre
Right. So still works then? That's cool.
Absolutely works brilliant
I also Calibre-web docker for accessing books when kindle not in hand.
What’s calibre?
If you’re in to reading ebooks this is important to have