Yep. There are seven million ebooks on Amazon and a fairly small minority of those have sold more than 10 copies. IN short: you have to market.
How? Well, that's a big question and you have to commit. But the answer is given (in a very tiny nutshell) in this blog post:https://jerichowriters.com/self-publish-book-amazon-kindle-kdp/
But really, to do this properly, you have to be more systematic than that. We've got a complete starter course for self-publishers available, free, to members of Jericho Writers. You can sign up for JW membership right here: https://members.jerichowriters.com/bazaar/full-membership/
Other services are available of course, but what I would say is that you stand next to no chance of making real sales (and ultimately making a living) from your work unless you proceed systematically and with commitment. Good luck!