Hello I'm Nepalese. Currently studying in mainland China. I already bought ticket

I already bought a ticket from the Internet (Beijing capital airport to UAE) I also havea a tourist visa to visit UAE. now I have checked ticket & fight it's from Cathay Pacific airlines & Hongkong transit (2.30hrs) do I need a travel permit to Hongkong or not? Can I go without any restrictions in Hongkong? If I can't, how to apply for transit permit through Beijing to Hongkong? How many days it takes to complete transit permit from HK consultant in Beijing how much I should pay for this?