It looks like the door bottom caught something like a curb. That isn't too bad to DIY straighten out by using a length of wood clamped along the outside of the door bottom in two or more places, protecting the paint first of course. Then use another clamp and smaller block of wood slightly larger than the pushed in area to pull it straight without going too crazy and crushing the door pinch/bottom. Basically you would be sandwiching the door bottom between two lengths of wood and forcing it to conform to the straightness of the wood. Polish out any associated scratches and/or use a small amount of touch up.
However, it looks like your door bottom also has some corrosion in the damaged area. If that's the only spot of "patina" on the door bottom, it's well worth saving the door and having a small amount of painting and blending performed. A small area on a door bottom will blend with the rest of the car far easier that an entire repainted door.
However, it looks like your door bottom also has some corrosion in the damaged area. If that's the only spot of "patina" on the door bottom, it's well worth saving the door and having a small amount of painting and blending performed. A small area on a door bottom will blend with the rest of the car far easier that an entire repainted door.