The corner of your wall may be "protected" with corner bead, a metal strip that is bonded to the wallboard and provides impact resistance. If you can see the metal surface in the chip, it may be that you need to prepare the surface to take the paint you use to cover it. Using a paint that is also a primer will help in that regard.
Abrade the surface as well as you can, perhaps extending to the paint around the chip. Ensure that the surface is clean, using an appropriate solvent. Acetone or similar material that will not damage the surrounding area, or even rubbing alcohol may serve the purpose.
If you use a paint that includes a primer and comes in a spray can, mask off the area around the chip to avoid overspray, or spray some into a container and apply with a small brush.
It's difficult to determine the depth of the chip. If too deep to simply paint over, you would still want to prepare the surface and use something like auto body filler putty (or bondo!) to get a good bond to the underlying surface. Any filler would have to be sanded to have a smooth surface for the paint, of course.