Hi mcfcok34,
HMRC is unable to advise you if it is worth you paying any shortfalls in your UK NI or for future years.
If you are living (and working) abroad, we would advise you to access the information online about living and working abroad Guidance on social security abroad: NI38 - GOV.UK (www.gov.uk).
This leaflet will explain about NI whilst you are abroad.
Guidance on social security abroad: NI38 Updated 12 May 2023
If you have a Personal Tax Account set up, you can check out your Pension Forecast through this.
You may also wish to contact Future Pension Centre
Check your State Pension forecast
Check your State Pension forecast - GOV.UK (www.gov.uk) Telephone: +44 191 218 3600) to decide if paying shortfalls and/or future years voluntary contributions will be beneficial for your future UK pension.
The application form for voluntary NICs (CF83) is contained within the NI38 leaflet.
Thank you.