In a small bowl combine ketchup, brown sugar, vinegar and mustard. Set aside.
In the instant pot set it to saute, add bacon and brown for about 5-7 minutes. Add the ground beef and onion to the bacon and continue cooking until the bacon and beef are thoroughly cooked. No need to drain the grease.
Stir in the beans, celery and sauce mix into the instant pot with the meat mixture. Stir completely.
Close the lid, turn it to "sealing" and click manual high pressure for 12 minutes.
Let it naturally release if you have the time, if not do the quick release after about 5-10 just be very careful with this step.