The motherboard spacers are never built-in because motherboards only implement a subset of all possible mounting hole locations for the different ATX motherboard format variants.
The studs come in a parts bag or box usually taped somewhere in the case that you have to install yourself in locations that match your motherboard's holes.
I just got the case, the stand offs are already in there i think. There was only one standoff in a little bag with other screws. There are tall stands that i can place the motherboard on and screw them. Those are probably it
Make sure you remove any that might not be in the correct locations for your board since those might short out board traces and pins, potentially ruining the motherboard.