It looks like this unit here: https://www.yes4pets.com.au/products/yes4pets-green-large-chicken-coop-rabbit-hutch-ferret-guinea-pig-cage-hen-chook-cat-kitten-house
Looks like the hinges for the run door are installed inverted. That may be all that you need to fix to get it to close. (https://www.yes4pets.com.au/cdn/shop/files/CC214.alt_2.jpg?v=1730286090&width=600)
I couldn't find the manual, so my best assessment is that there is some sort of latch that can be opened and locked for that door in the run. You can check the run door to see if there is a hole along the side which will help with the orientation. If there does not appear to be a latching mechanism you might be able to get a small piece of wood, with a hole drilled through, to the side of the run door as well as the bottom of the run and that 'key' can be inserted to keep it closed. I don't think you will need that 'key' specifically though, just a long wooden or medal dowel that can be fashioned and is thin enough to fit through the existing hole from the outside to reach and secure the door closed.
Wishing you the best in your project there!