The best way to fix a chip in a laminate countertop is to use an epoxy-based adhesive. First, make sure that the area around the chip is clean and dry. Then, apply the adhesive to the chip and allow it to dry completely. Once it's dry, sand the area around the chip until it's smooth. Finally, paint over the area with a matching color of paint.

If the chip is small, you can try to fix it with epoxy. If the chip is too large, or if there are several chips, then you will need to replace the entire countertop.