Question on PAYE Notice of Coding

Dear HMRC I am currently filling my self assessment for financial year 2023-2024, and the online SA form asks me the following two questions: 1. "Amount of underpaid tax for earlier years included in your tax code for 2023-24 (from your PAYE Notice of Coding)" 2. "Amount of estimated underpaid tax for 6 April 2023 to 5 April 2024 to be included in your PAYE tax code for 6 April 2024 to 5 April 2025 (from your PAYE Notice of Coding)." I do have some underpaid tax for the financial year 2022-23, and HMRC has already been automatically collecting this owed tax after changing my tax code in summer 2023, and I was notified by an online message in my Personal Tax online account about this. I did not receive a paper form of PAYE Notice of Coding letter during summer 2023. In the beginning of tax year 2024-2025, I reported to HMRC about some gift aid donations I made during tax year of 2022-2023, and therefore HMRC once again modified my tax code in summer 2024 to show the correct owed tax amount for my tax year of 2022-2023, and I again received a new message in my online personal tax account notifying me the change of my tax code. Again I did not receive any paper form of PAYE Notice of Coding letter for this. So in order to answer the above two SA form questions on underpaid tax, for question no. 1 should I put the owed tax amount as shown in the old online HMRC message sent to me in summer 2023? Or should I put the more accurate and correct owed tax amount as shown in the new online HMRC message sent to me in summer 2024 for question 1? My tax code in summer 2023 and summer 2024 were different due to the above two changes of my tax code. And since I only owed HMRC some tax for the financial year of 2022-2023, should I put "zero" for the above question 2? Many thanks in advance.

Hi, 
On your personal tax account Personal tax account: sign in or set up you will be able to view the last code operated for the 2023/24 which would
show the details needed to answer the 2 questions.
If you are unsure you will need to contact HMRC to access your record to check the details Income Tax: general enquiries
Thank you.