With regard to your underlying problem (of not being registered with a GP practice in Northern Ireland, you can find practices in your area via this link:
https://www.nidirect.gov.uk/services/gp-practices
The NIDirect website states "If you live over a certain distance away from a practice, or if it has closed its patient list, the practice may refuse your application. If this happens, you should contact the Business Services Organisation and ask them to put your name on a doctor's list in your area".
You can contact the BSO by emailing
[email protected] or by phoning 030 0555 0113. Their postal address is 2 Franklin Street,
Belfast BT2 8DQ.