Paying NI gaps by bank transfer from abroad

I have to pay my NI gaps and received a letter from HRMC with respective NICs shortfall rates for each Tax Year (from 2015 to 2024). I will be paying from overseas by a bank transfer. My question: Do I make individual payments for each Tax Year or make one payment for all Tax Years as a one total payment? I made one payment already for one Tax Year (in May 2024) but it is still not reflecting on my HRMC online records so I just want to pay the rest in one go if possible.

Hi,
You may pay your voluntary National Insurance contributions either one tax year at a time or multiples in one go.
May I ask that you call our National Insurance Helpline on 0300 200 3500 (from the UK) or +44 191 203 7010 (from overseas) about your payment that you made in May 2024 and they will be able to arrange for it to be allocated to your National Insurance account.  
You may wish to have your payment details handy when you call.
Thank you.