This is supposed to be flat, but got bent in a move. Because it is bent, it will no longer hold the trey properly. I have seen to use a torch, but the best I have is a candle lighter.
I have very little experience with things like this. I also have very limited tools, basically pliers, hammer, blow dryer, and I was thinking maybe the oven?
Bend it back
Here is how you could do it. Find a flat stone or brick. Use it to pinch the bent part against flat ground. Stand on the stone or have a helper stand on it.
The part on the handle will be sticking up. Gently push it down so it too is flat against the ground.
This will be more gentle and not mar the metal with hammer strikes.
Find a paver stone or brick high enough to put it on it
Put it on it and hammer it straight cold, not heat.
Try hammering from both sides
If you have one of those tiny hammer, it will not work.
Now to another possible problem. That is a design flaw. The large screw hole has left only two narrow stripes, weakening the construction. Now that is bend, bending it back might lead to failure (broken off piece)
I have successfully resolved this kind of problem by using an adjustable spanner or crescent wrench. Tighten the spanner as much as posible and use it to grab the bent metal strip. The long handle will give plenty of leverage.
You can even cover the spanner jaws with electrical tape or duct tape to protect the piece's finish.
Another option is this: It looks like there is an eyelet to bolt this piece. You can use this eyelet and the largest bolt that fits to secure the piece against a wooden plank or some lage-ish scrap of wood. Bolt it upside down (The piece would look like an "L". The _ would be the metal strip and the | would be what appears to be square tubing) such that you can stand on top of the plank, then use the hammer to un-bend by hitting outwards the vertical part of the "L". Again, you can use thick tape or cloth either on the piece or the hammer to diminish damage to the paint.
