How I can pay for visa

If the application is submitted to the Hong Kong Immigration Department directly by post, the fees in the form of a cashier order or a bank draft should be sent together with the application. The cashier order or bank draft should be issued by a bank which has a connected bank in the HKSAR and made payable to "The Government of the Hong Kong Special Administrative Region".

I know it but which banks? Thank you

Any bank which has a connected bank in the HKSAR. You can contact with Hong Kong Immigration for detailed information.