How do you fix cracks in air dry clay?

This is a normal happens situation with air dry clay. The air-dry clay will shrink when it dries. You can use these ways to reduce cracks.

When you make creation and notice some cracks, you can use a clay tool to fill up or some new clay to fill up the cracks. or Let the clay dry out completely, Once dry, create a new clay (use the same clay you’re working with) and fill it up.