Turn Instant Pot to Saute.
Add butter and let melt. Add celery and onions and cook about 4-5 minutes until they begin to soften.
Add bacon and cook an additional 4 minutes until bacon begins to crisp.
Add chicken broth and scrape the bottom of the pot to deglaze it - get up all the little browned bits.
Add reserved clam juice, but not clams.
Add in diced tomatoes, all the seasonings and stir well
Add in potatoes and carrots
Put lid on and close sealing valve
Press the pressure cook button and cook on high pressure for 5 minutes.
Do a quick controlled release when the soup is done cooking.
Add clams and stir. Let sit 2 minutes so the clams heat through in the hot soup.
Serve. Makes 8 servings. (I weigh out the entire batch of soup in grams and divide by 8 to figure out how much soup is in each serving. Each serving is approximately 1 1/2 cups of soup