Add oil to Instant Pot and select SAUTE. When oil begins to sizzle, brown meat in batches until all meat is browned; do not crowd. Transfer meat to a plate when browned.

When all meat is browned, add garlic to the pot. Cook for 1 minute.

Add orange juice, coconut aminos or tamari, sesame oil, red pepper flakes, and orange zest to the pot. Add browned beef and any accumulated juices. Select HIGH PRESSURE and set timer for 12 minutes.

When beep sounds, turn Instant Pot off and use a quick pressure release. When valve drops, carefully remove the lid.

Add the sliced bell peppers to the pot. Combine the arrowroot, or cornstarch and water, whisking until smooth. Add mixture to the sauce in the pot, stirring constantly. Select SAUTE and bring to a boil, stirring constantly until sauce thickens.

Stir in green onions and serve over rice. Garnish with additional orange zest, green onion, and red pepper flakes, if desired.