Add onions ,carrots, celery in one layer in the inner pot.
Add the beans and all other veggies(except Spinach) on top of it.
Pour in the vegetable stock ,Olive Oil, salt and pepper.
On top of all of this, add the tomatoes, select PRESSURE COOK at High Pressure for 3 minutes. Close the pressure valve.
Let the cooking time finish, wait for 5 minutes before quick releasing the pressure.
Open the pot ,taste the soup, add more salt if needed. Add spinach, close the pot and let it wilt in the residual heat of the instant pot.