Adobe Digital - how to authorize multiple devices to read purchase ebooks

I have purchased an ebook for school purposes and need to be able to access it on other devices not just my laptop.  I have seemed to follow every direction correctly yet I cannot open it on any other device except for my laptop.  please lay out step by step how to rectify this,  When I go on the laptop and try to authorize devices it says that you can only authorize a computer that has not been used to authorize previously another other computers or devices.

please provide support asap.

CoryLynn