How do I assemble back seat

Seems to have misjudged how the this part of the back seat goes back? If you look to your far left the 'thing' with the two holes in it, well one of them needs to fit to the squared area and I cant for my life remember how

I have a screw, but theres nowere for it to screw into, and I dont think there was a bolt on the other end either as it would have been in the bag