回複：what is the "the HK Post General"?

HK Post Office General, yes, you need to pick up the passport. Central Station MTR, HK Post Office General EXIT.

You can pay the application fee at Dah Shing Bank, it is by Exit C "Huang Qiu Da Sha" of Central Station of MTR. The bank opens at 9:00 am. After you pay, you can either walk to the consulate (about 10-15 minutes) or take the taxi. Strongly support you to pay the fee one day earlier.

You need to present your Employment Verification Letter and I-797 original copy and maybe your business card.

It is the most convenient way to apply for H1-B. No appointment needed.