Opening an E-Textbook Error

I am trying to open an E-textbook I had to purchase for a class from XanEdu and I want to open it on Adobe Acrobat Reader so I can use the Read Out Loud function. However, I am unable to open it there and I either get a message that it is password protected or it takes me straight to Adobe.com where the URL says https://www.adobe.com/404.html. I am able to phsyically read the textbook on Adobe Digital Editions but I want to use the Read Out Loud function on Adobe Acroboat Reader.