Rinse rice under cold tap water until water runs clear. Soak rice in a bowl of water for 1 hour.
Combine coconut milk, chicken stock, sugar, and salt in a multi-functional pressure cooker (such as Instant Pot®).
Drain rice and stir into the pressure cooker. Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 5 minutes. Allow 10 to 15 minutes for pressure to build.
Release pressure using the natural-release method according to manufacturer's instructions, about 10 minutes. Unlock lid and open carefully; fluff rice with a fork.