Very carefully put the chick into a tea cup--one that is big enough to keep it in without jumping out. Keep it in the incubator. The yolk is not absorbed. Hopefully id is not infected.
The chick needs to stay in the cup sitting up. It would be a good idea to give it some baby drop vitamins without iron. A drop twice a day.
The yolk should absorb by tomorrow. If it ruptures the chick usually bleeds out.
Keep it as comfortable as possible but you might have to cull if it seems to be in pain.
did the chick hatch by itself?