Obtaining NI number from abroad

Hi, I was born in the UK and lived there up to age 13, before moving abroad - so I did not receive a NI number at 16. I am now over 18 and would like to make voluntary NI contributions on the basis that I lived in the UK for more than 3 years, which is the requirement to make class 3 contributions. How can I get a NI number from abroad so I can make a CF83 application to pay voluntary contributions? Thanks.

Hi
Please look at the information on the link about who can have a national insurance number and how to apply.
Apply for a National Insurance number