Thats the idea, but only to get the Steam key, while they have a seperate purchase that give you the game for Itch only.
But due to the current predicament with Credit Card Processors forcing adult games to be shut down, they cant sell anything on Itch anymore.
So your only way to get the game for Steam, is to go to the steam store and buy it.
But Steam is also having these problems with Credit cards being blocked, so its only a matter of time that Steam might end up in the same fate.