Yes you need to amend if you didn't make a separate IRA contribution and delete it. It may affect other things. And when you turn 72 the IRS will be expecting you to take a distribution from an IRA you don't really have.
How to amend a 2020 return
https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-return/00/27439
