Help! How do I correct 1 listing policy violation duplicate ASIN product detail page

I’m a small time seller mostly selling my own books I don’t need anymore. I’ve been doing it off and on for many years, and I recently got dinged for a policy violation for an issue I was unaware of. Apparently I listed a book under a pre-existing listing that turned out to be a duplicate ASIN. So I am now in trouble for “duplicate product detail pages” for one book. Amazon says my account health is now at risk and has removed the listing. They want me to take “corrective action” but I’m not sure what to do since the listing has already been removed. How do I fix this so my account health is restored?