This article explains how to change your county for app store purposes.
Apple iOS/App Store
Open the Settings app.
Tap your name at the top of the screen, then tap Media & Purchases.
A pop-up will appear at the bottom. Tap View Account. You might be asked to sign in.
Tap Country/Region.
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Tap Change Country or Region.
Tap your new country or region, then review the Terms & Conditions.
Tap Agree in the upper-right corner, then tap Agree again to confirm
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.*