Catchers box?

[parrothead]

Playing in USSSA fastpitch tournament this weekend, last inning tying run on 3rd winning run on 2nd. Team wants to intentionally walk batter - told need to throw the pitches (I think maybe HS is only place where you can just declare intent to walk)

Then the Catcher sets up basically straight on from the left handed batters box, and this is where my baseball background has some confusion. In baseball play that calls balks if Catcher at time of pitch is outside the catchers box, its a balk. Must start in box at time of pitch then move out.

Is there a similar size catchers box? Is there a similar rule?