Press the SAUTE button on the Instant Pot, and press it again to bump it to SAUTE MORE. Heat the olive oil in the Instant Pot. When hot, sauté the onion and garlic until softened, 5-7 minutes. Stir in the taco seasoning. Add the quinoa, water, salt, beans, corn, tomatoes, and salsa. Press CANCEL.
Close and seal the pot, and pressure cook on MANUAL for 10 minutes (high). Carefully QUICK RELEASE. Gently shake or tap the pressure cooker, and then carefully open away from you. Taste and adjust with more salt, if needed. Serve as-is, or topped with pepitas, sliced avocado, cilantro, and salted yogurt.