Under the ingredients list it says:

"Pectin - get the "no sugar needed" type. (it's a natural product, made from apples and available at grocery stores (season - spring through late summer) and local "big box" stores. It usually goes for about $2.00 to $2.50 per box."

So you would use the usual 1 box of pectin just as with most recipes that call for powdered pectin.

Dave