Agree with posters; today’s gasolines have quite a few additives already in them. We’ve driven cars to over 300,000 miles without any additives other than the odd bottle of “gasline antifreeze” in very cold weather.
Years ago I recommended an additive called “Karbout” to my father-in-law. He only did short stop and go trips in his carbureted Buick and ran a very rich fuel mixture. Today’s computerized cars with fuel injection don’t have those problems anymore.
If you are having problems with your fuel induction system, look for the real causes and fix those.