How do I change country on my iPhone?

If you’re really trying to change countries of your Apple persona, see what you need to do in the article linked below.

It’s a bit more “involved” than a simple setting; note that you’ll need a payment method in your new country.

Change your Apple Account country or region - Apple Support

You can change your iPhone’s region by going to Settings > General > Language and Region > Region > Then select a new one from the list.

You can change your Siri’s region by going to Settings > Siri > Language > Select a new one from the list.

You can change your App Store’s region in the App Store app > Tap your profile in the top right > [your name] > Country/Region > Select a new one from the list.

There are many region options on iPhone, but they should all be set to the same for a seamless experience. Without enough information, you only leave us guessing.