However, there were no proper instructions apart from a few diagrams on a paper. As such, I was left with the question of where certain types of washers were supposed to go. And I’m not sure if a washer was needed where I connect the screw to the holder which keeps the wheel tray in place, because it was a little finicky.

https://www.amazon.com/Swagman-Cross-Country-2-Bike-2-Inch-Receiver/dp/B0001VO1YY