The most common reason for an eBooks not to show up on a computer browser is due to a pop-up blocker setting on your device. Please see below for steps to modify this on various browsers

1. Safari . Go to the site that you want to allow the pop-up from. In the top right hand corner choose Safari > Preferences>security. If the “Block Pop-up” option is selected you will not see your e-book content. You can select “Allow” (which will allow all pop-up content) or (recommended) “Block and Notify” which would give you the option in the top right hand corner of your browser to “allow” specific pop-ups such as your eBook
2. Chrome . Go to the site that you want to allow the pop-up from. Look for the following symbol in the top right hand corner of your browserIf you click on the symbol you should be given an option to “always allow pop-ups and re-directs” from that particular site. Once selected and approved the eBook should open.