The game is out at this point, but no. Buy itch io version as you also get a Steam key. You also won't be supporting Steam that way, so that's a big bonus (in my opinion at least).
How did I come to this conclusion? Because I got a Steam key after purchasing this game on itch io (I don't buy on Steam anymore after a certain Steam library "update" was made mandatory). Look at this Steam thread: https://steamcommunity.com/app/1546860/discussions/0/3095635055516419785/
All you need to do is contact habupain on this game's discord.