Just to get an answer for those interested, I sent them a message to ask whether they welcomed people from this side (and LGBTQI+ while I was at it - 'asking for a friend', you understand

)...
Here's their response : -
Hi Keith. I would love too but I believe a Greek Cypriot mobile number cannot dial a Turkish Cypriot number. This is usually how the introduction is first made.
I will get back to you soon as I will have a little think about it.
Merry Xmas
Louise
LBGTQI we are a very young website but do have plans for all sexual orientation in the future. Watch this space x
So there you are! — a GC or UK 'phone number (or 'other', of course) would seem to be required at present.