non eea family member permit

[bangash]

hello,i need some advise please if any body can resolve this issue for me,
my cousin is 18 years old and he live in pakistan,he was born in denmark,his parents are danish national as well,who them as was living in pakistan from last 3 years,

i need to ask is that my cousin want to come to england permanently along with his parents,so far i know there parents can come to england without any concern as they are danish national but issue comes for my couisin,how can he join them as well,

first thing does he has to apply to EEA family permit on behnalf of there parents,
or
there parents has to come first UK and then they can apply for there child,
i am little confuse ,how my cousin can go with there parents or is it possible he can go alone on EEA family permit without the need to there parents to be n uk or go with them,

my cousin hold a pakistani passport,he been to denmark but denmark deny him to give him nationality as when he was born in denmark there parents did not register his son on there passport,

please can anybody help me with this