Self-employed in the UK and non-UK-resident: paying class 2 NICs from abroad in Self Assessment

Hello, I have been living in the UK for several years, working as self-employed. I moved abroad (EU) 1.5 years ago but I am maintaining my status as self-employed in the UK as a second "job". I would like to pay Class 2 NICs until my retirement age through my Self-Assessment where I declare my UK self-employment income. I lived in the UK for half of the fiscal year 2022-23 (split year). Last fiscal year 2023-24 was the first full one as a non-resident. When I filed my Self-Assessment for the 2023-24 tax year, I was treated as having made Class 2 NICs (profits between the small profits threshold and the lower profits limit). In my personal tax account I have contributions from self-employment for 52 weeks in 2023-24. I have just found out about the Class 2 NIC residence requirements and being self-employed. I am confused. Now I don’t know if I have to apply to pay “voluntary” Class 2 NICs while abroad (CF83), or if I can continue to do so through my Self-Assessment while being self-employed in the UK, as I did in 2023-24 (contributions from self-employment). Thank you in advance for your help.

Hi Paul-50,
You will need to write to HMRC to request a liability decisionc, please provide the following information in your letter: 
    your full name
    your National Insurance Number
    your date of birth
    your most recent UK address
    your address abroad
    the type of work you do
    your business name and address - both UK and abroad
    where your contract is held
    how often you work in the UK
    your normal working pattern (the days, weeks or months they regularly work)
The address to write to is:
PT Operations North East England
HM Revenue and Customs,
BX9 1AN
Once HMRC have this information, they will be advise you of the correct action to take.
Thank you.