Since no official demo exists for download, interested players can find the full game on major digital storefronts:
The is a myth—but that doesn’t mean you can’t try before you buy. Use Steam’s refund policy as your modern demo. In under two hours, you’ll know whether the icy streets of Gotham and the young, brutal Batman resonate with you. Batman Arkham Origins Demo Download Pc 13
If you're specifically looking for a version marked "13", it might be a custom content or part of a promotion/event that isn't widely available or supported anymore. Since no official demo exists for download, interested
There is for Batman: Arkham Origins on PC. Batman Arkham Origins Demo Download Pc 13