Methods:

Dice slice, and mince all vegetables, set aside
Sauté onion and carrot in 1 cup of broth for about three minutes. Use the sauté function and sauté in the Instant Pot. Watch the bottom of your pan so that the broth doesn’t dry out and vegetables begin to stick. Your pan might not come to pressure if the vegetables stick.
Add in all other ingredients: lentils, canned diced tomatoes, celery, potatoes, garlic, seasonings, vinegar and lemon juice, and remaining four cups of broth. Give it a stir.
On manual mode, set your pressure cooker on high for 12 minutes.
After the veggie soup has come to pressure and counted down, allow a natural release for 10 minutes.
After you have allowed 10 minutes for natural release, carefully with a long-handled spoon or similar device, continue releasing pressure. Open your pot.
Depending on how thin you like your soup, you may want to add in a little vegetable broth. Add salt and pepper to taste.