You can use either the Aussie Traveller. FULL roll out types.
Cut to size.

Or one of those cheaper things that fit on side of racks.

I have both.
One on van. One on Ute.

The cheaper ones have advantage of light. simple. easy to blow off.
Plenty of extra rooms. sides. Flyproof rooms etc to add.
For near zero $$$'s.

I had different one on Rear door van decades ago.

Across rear of van to extend length. (Over door) 8 ft 6in long.
width of van.
All rolled up into a bag with legs and velcro's permanently fitted for use.
That. with Aussie Trav along the side.
Doubled the size of covered camp area.

Office Air cond on Blue Plastic 44gal drum outside bed window.
Perfect for the camp.
Sold on to van next door when departing.
Permanent van park. No longer exists.

We Used as a base while Di checked out the area out to Broome
ONCE. No thank's. East Coast fine.

Bit awkward. But from memory "I" managed for the one trip we had van.
Adel Darwin Adel 3 months.
Find somebody with one (Ask Dealer for ph no.) and try.