Hank here from Shopify.
Thank you for confirming you are based in Hong Kong, as it allows me to share with you the correct information to assist.
We have a wide number of payment gateways available for you to use within Hong Kong.
While Alipay Global and PayDollar are both available, each provider offers different methods that they support so reaching out to them directly would be the recommended advice.
That said, to see which options are available to you, you can see this within your Settings > Payments > Alternative Payments section of your admin, where a full list of gateways is available to you.
Let me know if you have any other questions!
All the best,
"HSBC PayMe" is also a very good payment gateway for Hong Kong region.
But by default it is not available on Shopify list, but can be integrated to shopify stores via Hosted SDK method.