RMD was missed

I have a takeover profit sharing plan. The owner turned 72 on 12/31/22 and did not take the RMD.  My understanding is he should have taken the distribution by 4/1/23.  Can someone please explain the consequences of not taking the RMD by the required beginning date and how to best remedy the situation? 

I just watched a recorded webcast where it was said the IRS could (would?) waive excise taxes if self corrected within 180 days. Given you're within that time period (and still the same tax year) I would do that. Worst case, I believe, is a 10% excise tax if corrected timely.