How Can I Set a Payment Unit by Country with Flutter Pay? - flutter

Question

How can I determine currencies by country? I am receiving payment transaction using Pay with Flutter plugin.
How can I make the following values in USD for America and TRY for Turkey according to the user's country.
"countryCode": "US",
"currencyCode": "USD",
const String defaultApplePay = '''{
"provider": "apple_pay",
"data": {
"merchantIdentifier": "merchant.com.sams.fish",
"displayName": "Sam's Fish",
"merchantCapabilities": ["3DS", "debit", "credit"],
"supportedNetworks": ["amex", "visa", "discover", "masterCard"],
"countryCode": "US",
"currencyCode": "USD",
"requiredBillingContactFields": ["emailAddress", "name", "phoneNumber", "postalAddress"],
"requiredShippingContactFields": [],
"shippingMethods": [
{
"amount": "0.00",
"detail": "Available within an hour",
"identifier": "in_store_pickup",
"label": "In-Store Pickup"
},
{
"amount": "4.99",
"detail": "5-8 Business Days",
"identifier": "flat_rate_shipping_id_2",
"label": "UPS Ground"
},
{
"amount": "29.99",
"detail": "1-3 Business Days",
"identifier": "flat_rate_shipping_id_1",
"label": "FedEx Priority Mail"
}
]
}
}''';
I tried to do it with the codes in the getCurrency() method above, but it adjusts according to the device language. Idont want this.
String getCurrency() {
//var format = NumberFormat.simpleCurrency(locale: Platform.localeName);
Locale myLocale = Localizations.localeOf(context);
return myLocale.countryCode ?? "";
}