Hi ! So I had a relative call HK Airlines for me to ask - they advised that we would receive a check-in email which would provide the relevant information. My understanding is that HK Airlines allows online check-in at 48 hours.

I can pop back in and update in a few days - my parents are flying the YYZ > NRT / NRT > HKG in a few days. So their 48 hours should be coming up soon.