Do I need to pay gambling tax?

No need, just like somebody won in the jockey horse racing, they can collect the money and leave.

Gambling tax is for the company who run the game not for the one who won the game.

( I know in foreign countries, the winner had to pay tax, HK & Macao, not necessary)

The answer is negative.

All gambling taxes have been paid by the relevant companies. If you win in the Mark-six, the Hongkong Jockey club has reserved a portion in the betting pool for taxation, the money they announced and you get is after-tax portion.

Same thing applies to Macau, so the teenage girl does not has to pay tax.

Of course, in most of the western countries, they have a different tax system.

No. Unless you are professional gambler.