When you get to world 2 and beat the first level, it will ask you to enable ghost miis and miiverse. Say yes, and select "post." You can then use your stamp(s) in the draw tool.

thanks!

@liam ummm... the post feature via the game doesnt work, it gives me an generic error

u need too pay

hola

real

posting in mario 3d world is currently only avabile for the beta testers which you have to pay for, its not avavilbe for everyone