Need help to getting 6 pack abs when I'm underweight already?

I have Hugh metabolism and i need hel getting six pack abs, u can see the outline but I want people to really notice them please help me to achieve my goal. I weigh 116 I am gonna turn 16 April 16. I am 5 foot 6 inches tall. Ways to get six pack abs to show more when I'm already underweight thanks so much foe helping me!