If users can't find your book on the store then do these:

1. Make sure the Book's title is not too long. Not more than 21 characters

2. Make sure it's published. You can check this by going to MY PUBLICATIONS or MY WORKS on the website. If it says Saved then it's not published. If it says Published then it is

2. They can search for your name i.e Magnus. This will show all books published by that user

3. If your book is an Adult book, it will not show on search unless SHOW ADULT is turned on. See screenshot attached below: