Press the Sauté button on the Instant Pot® and heat oil. Add carrots and onions to pot and cook until tender, about 8 minutes. Add mushrooms and cook until they just soften, about 3 minutes, then add garlic, ginger, and soy sauce and cook until fragrant, about 30 seconds. Press the Cancel button and add broth and tofu to pot. Stir well. Close lid, set steam release to Sealing, press the Manual button, and set time to 6 minutes.