Hi gelo241,
Thanks for visiting the Apple Support Communities. You can find instructions on how to change your Apple ID country/region in the Apple Support article Change your Appel ID country or region - Apple Support. The specific steps below, taken from that article, detail how you can do this on an iPhone:
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 you still need help after that, you can reach out to Apple Support directly. They will be have access to additional tools and resources to assist. You can get in touch with them here: Get Support.
Have a wonderful day.