Windows 10 can't download apps

Hi all,
I'm posting this in Ebooks, Technology & Operating Systems because I don't know where I should post it?

I use eyegaze given to me from my local OTs because I can't use my hands.

I can't download any apps to it because of restrictions and I need an ebook reader that can read epub books.

I can read kindel books via a web browser. Does anyone know how I can read these books without an app?

It's windows 10 on a Dell tablet.

Thanks all