If we have a leaver from the previous month but paid this month for pay in lieu of notice, what would be their leaving date on the P45

With this particular employee - they left 28/03/2024 but paid PILON through April Salary, now that has been paid we are running the P45 but should we put March date (the last day they worked) or April (the last day they were paid)

Thank you in advance for the advice.