Heat pressure cooker over medium heat; cook chicken until browned, 2 to 3 minutes per side. Sprinkle paprika, salt, and pepper onto chicken.
Combine onion, chile sauce, water, and vinegar in a bowl; pour over chicken.
Cover pressure cooker with lid and cook according to manufacturer's instructions, about 15 minutes. Remove from heat and release pressure through natural release method; open pressure cooker carefully.