Install the version of EpubReader for your chosen browser - either:
EpubReader for Microsoft Edge,
  EpubReader for Chrome Browser,
  EpubReader for Firefox

  At the top right of the browser this new added button will show where to
  open the EpubReader in future.


Then either Download the free ebook at Here or
just Read the ebook without downloading.

and the ebook will be stored in the Downloads Folder and also opened.

  At the right and left edges you can turn the pages Forward → and back ←.

  Clicking in the middle of the current page will show the buttons to the

  Contents, Settings (SET WIDEMARGINS!), and Choose another ebook.