What to do when took withdrawal from non-deductible IRA opened years ago without f filing Form 8606?

I took RMD for the tax year, 2023, from my non-deductible IRA which was opened many years ago. I remember that when I opened this non-deductible IRA, I did not file Form 8606 because I did not know it was required. Actually, I just learned about Form 8606 here. What should I do? Thank you.