curl --request GET \
  --url https://api.returnshelper.com/uat/public/api/Country/getAllCountries \
  --header 'x-rr-apikey: <api-key>' \
  --header 'x-rr-apitoken: <api-key>'

{
  "countries": [
    {
      "countryCode": "<string>",
      "countryName": "<string>"
    }
  ]
}