TL;DR: AT&T fucked it up like everything they touch.
It's out on DC:Universe in the USA. Outside the US, I think it's available as part of Crave or even Netflix. Despite it being owned by AT&T, it is not on their HBO Max platform. Max doesn't mean what you think it means, because of AT&T. This is purely AT&T being AT&T by not having a clue as to what consumers find worth in. Despite them owning the content, they're rotating their titles in and out of the service. They also don't have their app available on the Amazon Fire and Roku Platforms. Way to disinterest the majority of streamers by not having your own materials available at all or not available on the mainstream platforms.
With that said, it is available via magical means...