how i do to make a fighting game multiplayer without have to program all again?

i want make a fighting game, and put the online, but i dont wanna program all the inputs and things again, someone know how i make to just program the connection of inputs

You're going to need to be a LOT more specific to get an answer.

e.g....

What do you mean by a fighting game? (people have different definitions)

Where are the inputs already?

What have you made it in already?

What are 'the things'?

What is 'connection of inputs'?

Do you basically want to make a game without doing any coding? In which case, you can't.