The thing about ETF market in Hong Kong is that they are illiquid.
Even for HKD denominated symbols, the bid-ask spread is huge and the minimum tick size is also huge, and there are transaction fees like stamp duty.
The securities regulatory regime of Hong KOng allows opening a stock trading account remotely by submitting online forms to registered local brokers. The difficulty is finding a local broker that adopted such framework. There are probably fewer than 5 local brokers that offer this.
https://www.sfc.hk/edistributionWeb/gateway/EN/circular/intermediaries/supervision/doc?refNo=19EC46
Instead of reinventing the wheel, I suggest that you buy a US-listed equivalent ETF that tracks "A Shares, B Shares, H Shares, Red Chips, P Chips, S Chips and N Shares" in a similar manner.
For example, iShares MSCI China ETF (MCHI) listed on NASDAQ has $6 billion AUM and closely tracks the China Total Market, and is even more liquid as shown in the chart below.
Blue = MCHI on NASDAQ, Red = 9169 on HKEX