Hi sir this is sameer mamun nationality of Bangladesh

Yes, it is available in Bangladesh.
Those documents are needed: copy of your passport, proof of your financial standing, the application form, a half-length color photo, flight itinerary, hotel booking record, and your travel plan.
Bank statements are needed, but I cannot tell you for sure how much money you need to show up in bank account. You should prepare at least USD 100 per day if you want to visit HK.