Cool. I’m trying to suggest workarounds without waiting for @FRANK to do it. The program (I have the previous one, not the new one) essentially wants you to be able to do squats with weights heavy enough to do sets of 10, 6, and 3 (I’m simplifying) with a certain percentage of your one rep max for the squat. Thus you need a squat rack to get such a heavy weight on your shoulders.
I would expect that you would get pretty equivalent results if you can find a one-legged squat-type exercise that you could load heavy enough to do 10, 6 and 4? at certain percentages of your one rep max for that exercise. That is, loading with dumbbells, kettlebells, weight vest, whatever that does not require a squat rack to get the weight in place.