Changing location in GeotargetingWP using URL parameters or querys tring

functions.php

<?php
/**
* Allow users to change location with query string like this
* https://yourdomain.com?geot_country=US
**/
add_action( 'init', 'change_geolocation_with_url' );
function change_geolocation_with_url(){
  if( ! isset( $_GET['geot_country'] ) ) {
    return;
  }
  $iso = strtoupper( esc_attr( $_GET['geot_country'] ) );
  // update wprocket country cookie
  setcookie( 'geot_rocket_country', $iso, 0, '/' );
  // update cookie for dropdown widget
  setcookie( 'geot_country', $iso, 0, '/' );
}