Turn on a multi-functional pressure cooker (such as Instant Pot®) and select Saute function. Add oil.
Combine cornstarch, salt, garlic powder, and Chinese five-spice powder in a bowl. Toss chicken in the mixture to coat and shake off excess.
Saute coated chicken in the hot oil in the pressure cooker pot until golden brown, about 10 minutes. Remove chicken and allow to drain on a baking sheet lined with paper towels. Clean out the pressure cooker pot.
Turn pressure cooker on again and select Saute function. Combine orange juice, water, vinegar, coconut aminos, cornstarch, sugar, garlic, and ginger in the pot and cook, whisking regularly, until thickened, 5 to 10 minutes. Add cooked chicken and toss to coat.