The game most likely won't be released on itch.io, but it will most likely come to Steam.
That'll happen once all the chapters of Volume 1 are finished. Before you ask, I don't know yet how many chapters that'll be. And even then, the Steam release won't happen right away.
For now, if you don't want to pay for the game, you can simply wait for the public release on Patreon or SubscribeStar.