Definitely late but almost done with the puzzle and hopefully it helps anyone stuck on the puzzle

I need a little help with the puzzles. LOL. I can't seem to see where to get the key from the huge padlock across the bridge! I don't want to use a cheat code, but I really want to exercise my brain to look for clues. I'm used to playing puzzle games and this one really did a good job. I adore how they went on a concept like this and worked it out with a bunch of cans!