You cannot cover the sauce directly. Many sauces on the market are raw. It is best to stir-fry or cook them in the noodles. The flavor is more fragrant.
If you only have one electric heating cup, cover the noodles with sauce when the noodles are almost cooked, then cover the electric heating cup and cook for a while. Once the noodles are cooked, you can eat with confidence. This way the stew sauce will also be cooked.