Hello, the Steam version is different to Itch.io version in term of graphic due to a quality control process that I had to make sure it's all RTP.
So, if you got Steam version, you gotta prepare your own spritesheet or get some from asset store.
Or you can get it from artist Robocelot, but you'll need to edit his art, put them to spritesheet and stuff in order to use them with RPG Maker.