itch.io

No. Just no. I don't want to come off as hostile here, but do you even have an inkling of an idea of how multiplayer works?
Not only does Nose state in the game's description that he doesn't have the technical knowledge or experience to confidently implement multiplayer, the game itself has NO net code or architecture to facilitate it in the first place.

My personal philosophy is that if you are going to tell developers to do something, you better know what you're talking about, and be capable of making it yourself. But this single sentence tells me with absolute certainty that you don't. And if you think it's easy, then by all means, do it yourself, because you'll see just how hard it really is.