If you're worried you could try to assist. But read the assist info on page one first.
Personally, I would wrap it in a warm wet paper towel and pop it back in the bator for a while and see if it progresses any more in the next hour before assisting any further.
Keep the towel away from the pip area, but wrap the eggs sufficiently to provide humidity.
I don't like assisting unless I am sure there is a major problem (malpo, shrink wrap, etc.)
But I have used the towel trick many times, and in a short while they do it on their own.
You have to make the judgement if it needs an assist, you have the best information on the egg and chick condition.