You've got spiderweb cracks in loose paint. If you don't knock off all that chipped paint the problem is going to come back very quickly. If it was me I'd knock off all the loose paint with a screwdriver, sand it with a small sanding block or mouse sander, then spray primer and paint. The challenge with this is that with each step the repair area just keeps getting bigger. A cheap air brush from Harbor Freight can help you keep a small spray pattern. I transfer spray can primer to the air brush by spraying it into a small funnel into the air brush jar. A good auto paint store will sell you 2 - 4 oz. of color matched paint at a reasonable price.