the HK visa is required, it takes 4 working days for visa processing, however, if your application should be sent to Immigration Department of HK Government for approval, it takes 1 month. The requirements are:
1. Your Passport/travel document

2. One completed Hk application form affixed with one passport-sized photo.

3. an invitation letter in which the sponsor agrees to provide financial support and accommodation, and one copy of the sponsor's HK ID.