I would like to ask friends from Hong Kong how to use hashkey exchange?

I am a mainlander and want to legally trade cryptocurrencies in Hong Kong. I would like to ask a few questions and ask my Hong Kong friends to answer them. The staff of this exchange are the best. Thank you very much.

First, how to prove one’s 8 million Hong Kong dollars? Do I need to have these 8 million in a bank in Hong Kong? Are mainland bank deposit certificates or stocks acceptable? Or is it possible with real estate?

Second, can mainland citizens trade on this exchange? I am in Hong Kong, but I don’t have Hong Kong identity, I am just a tourist.

Third, can I borrow the identity of a Hong Kong friend to open an account? Is it possible to withdraw and deposit funds through a friend’s account? Does it violate local regulations?

Thanks for the answer. Many people are curious about these questions, and there are no reliable answers online. I'm looking forward to having professionals clear my mind.