How to use opencart for ebooks selling??

I am making a store for ebooks and I am new to opencart so, can anyone help me. I need to know a few things.

How to adds books to be purchased and then downloaded from the site.

Moreover after the book is sold to a particular person then that book should be available to him forever to be downloaded.

Last thing, is there a way to show the number of downloads per ebook??

You can add products as book then aside the downloadable file for equivalent products

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Thanks for your reply @alin. Could you also tell me, if someone bought a book then that would be available to him for unlimited downloads or there will be a set number of downloads allowed.