Board Thread:Questions and Answers/@comment-5.54.10.160-20140130030650/@comment-1824272-20140205170436

The PlayStation Store on the PS3 is a little annoying to find the Infinity beta in. It's in one of these three places:
 * New This Week
 * New This Month
 * Demos

However, that link you copied/pasted says it's the demo. So if you can log in to your account, and download it from that link, it should work. :)