Change dropdown widget country names

countries.php

<?php

add_filter('geot/dropdown_widget/countries', function($countries) {
  
  foreach( $countries as $i => $c ) {
      if( $c->iso_code == 'US' ) {
        $countries[$i]->country = 'USA';
      }
    
      if( $c->iso_code == 'GB' ) {
        $countries[$i]->country = 'UK';
      }
  }
  return $countries;
});