Rinse and dry squash. Cut in half width-wise and scoop out seeds.
Place steamer rack in your instant pot, along with water. Place both halves of squash, cut side up, on top of steamer rack. Squish them in a bit to make them fit.
Secure lid and make sure steamer vent in closed. Set to "Pressure Cook" for 7 minutes for "al dente" texture. If your squash is more medium sized, then you might want to increase to 8-10 minutes, depending on size.
Release steam, them use tongs to remove squash. Shred strands with a fork. Serve with your favorite sauce.