On a 2006 Ford Ranger, you need holes in the load liner for the jbolts to go through. They obviously go through the slotted brackets that are on the canopy first.
I assume on your Rodeo there is a high level brake light on the back of the passenger compartment. You might need to remove that for it to fit if it pushes the canopy too far back. There are different canopy versions where there is a ladder rack to the back of the cab. IW reckon the high level brake light needs to be inactive, possible because the canopy might reflect the red light forward which is a no-go. The previous owner of mine had also trimmed the outside flange at the bottom (I think he might have had some protruding bolts to work around from when he had shutter on the back).
There is an IW canopy and dimensions guide that I will attach. Also one which lists the canopy numbers that are attached to the side so if you see one at auction you can check if it fits your model.