PayMe is available on the Hong Kong iTunes Store. To change your account country or region to Hong Kong, follow the steps below:
On your iPhone, iPad, or iPod touch:
1. On your device, tap Settings > iTunes & App Store.
2. Tap your Apple ID. If you're not signed in, sign in with the Apple ID and password that you use with the iTunes Store.
3. Tap View Apple ID.
4. If prompted, enter your password again.
5. Tap Country/Region.
6. Tap Change Country or Region.
7. Tap your new country or region, then tap Next.
9. In the prompt that appears, tap Agree.
10. Select a payment method and enter your payment information.
11. Enter your billing address and tap Next.
On your Mac or PC:
1. Open iTunes.
2. If you’re not signed in, sign in with your Apple ID.
3. From the menu bar at the top of your computer screen or at the top of the iTunes window, choose Account > View My Account.
4. Enter your password, then press the Return or Enter key on your keyboard, or click View Account.
On the Account Information page:
1. To the right of Country/Region, click "Change Country or Region."
2. From the "Select a country or region" menu, select your new country or region.
3. Click Change.
4. On the Welcome to the iTunes Store page, click Continue.
6. Click Agree.
7. Enter your payment method.
8. Enter your billing address.
9. Click Continue.
For more information please refer to https://support.apple.com/en-hk/HT201389