My App Store won’t let me download tik tok in my own region only the region Hong Kong

Hello Tuna_1,

Please make sure that you've changed your region correctly as explained in this support article: Change your Apple ID country or region - Apple Support. Follow this guidance:

"What to do before you change your country or region

• Spend any balance remaining on your Apple ID. If you're not sure whether you have a balance, check your Apple Account balance.
• Cancel your subscriptions and wait until the end of the subscription period. 
• Wait for any memberships, pre-orders, movie rentals, or Season Passes to complete, and wait for any pending store credit refunds to process. You can cancel a pre-order.
• Make sure that you have a payment method for your new country or region. See what payment methods you can use.
• Redownload your apps, music, movies, TV shows, and books on any devices that you might use to play or read them in the future. Some types of content might not be available in your new country or region. Learn what types of content and services are available in your new country or region.

Use your iPhone or iPad to change your region

1. Open the Settings app. 
2. Tap your name, then tap Media & Purchases.
3. Tap View Account. You might be asked to sign in.
4. Tap Country/Region.
5. Tap Change Country or Region.
6. Tap your new country or region, then review the Terms & Conditions.
7. Tap Agree in the upper-right corner, then tap Agree again to confirm.
8. Select a payment method and enter your new payment information and billing address, then tap Next. You must enter a valid payment method for your new country or region."

If the issue persists, further assistance may be needed. We want to make sure you reach the right team for help with your iPhone & App Store, so we recommend that you contact Apple Support directly. Depending on your region, you may be able to reach them here: Get Support - Apple.

Thank you for participating in the Apple Support Communities and have a wonderful day.