can I apply for Hongkong visa in Phuket Thailand as Im working here at the moment ?

Hi there , Im a Vietnamese working in Phuket as a nanny for a foreigner family living here . They are gooing to have holidays in HK so I need to apply for a visa before enter HK as Its not possible for me to get visa on arrival.
Please let me know if for my case I can apply visa in Thailand ( Phuket) instead of getting back to Vietnam. And if so, Please let me know more details . Thanks.