EASA is pretty much useless in the UK and unless you have right to live and work in Europe you won't be able to get a job there. If you have EASA fATPL you will need to do CAA exams to get a UK licence. Rudestuff will be along soon to give a much clearer answer as my licensing knowledge is more about the more experienced end. Just for clarity a 'dual' licence doesn't exist - you may be able to do parallel training but they are two separate licences issued by two different licensing authorities (and incidentally two separate initial Class 1 medicals).
Good luck
ps get the Class 1(s) before spending a single bean on professional training.
pps
https://www.caa.co.uk/commercial-ind...-january-2023/