Hi im looking for the website to apply for hong kong visa online where can i find that?

i want to apply for a dependent Visa for my 4 year old son and a tourist l for my sister for 90 days and i currently have a work permit for 29 weeks, and we are South Africans and we need to be in Hong kong on the 17th march i have applied via consulate but the immigration hasn't replied regarding all the documents i have submitted. its been two weeks and a half now so i'm worried and i want apply online aswell so if anybody can help how do i go about that route?