Hi Orson
It's wired exactly the same as the other effects, it's just the output goes from the Volume pot instead of a wire from the board.
If you look at the first layout on the
Offboard page, the blue Output wire is instead the Volume 3 wire which goes to the pot. Volume 1 is connected to ground and then Volume 2 is the real output which goes to the top right hand lug of the stomp switch in the drawing
Good luck with your build