我正在发出 AJAX GET请求，但收到的响应不符合预期。响应通过，但PHP变量为空。下面是我的jQuery：

jQuery(document).ready(function($) {
   $.ajax({
      url: '/wp-admin/admin-ajax.php',
      method: 'GET',
      data: {
         action: 'geoip_detect2_get_info_from_current_ip',
      },
      success: function(response) {
         var country = response.country.names.en;
         var isoCode = response.country.iso_code;
  
         console.log('Country: ' + country);
         console.log('ISO Code: ' + isoCode);  
      },
      error: function(xhr, status, error) {
         // Handle any errors that occur during the AJAX request
         console.error(error);
      }
   });    
});

更新的 AJAX 请求的答案

$.ajax({
      url: '/wp-admin/admin-ajax.php',
      method: 'GET',
      data: {
        action: 'geoip_detect2_get_info_from_current_ip',
      },
      success: function(response) {
        var country = response.country.names.en;
        var isoCode = response.country.iso_code;
  
        console.log('Country: ' + country);
        console.log('ISO Code: ' + isoCode);
  
        // Store the values in hidden input fields
        $('#hidden-country').val(country);
        $('#hidden-isoCode').val(isoCode);
      },
      complete: function() {
        // Retrieve the values from hidden input fields
        var country = $('#hidden-country').val();
        var isoCode = $('#hidden-isoCode').val();
  
        // Make an AJAX request to your PHP script in the theme
        $.ajax({
          url: '/wp-content/themes/bethub/inc/product_layout/side_block.php',
          method: 'POST',
          data: {
            country: country,
            isoCode: isoCode
          },
          success: function(response) {
            console.log(response);
            // Handle the response from your PHP script
          },
          error: function(xhr, status, error) {
            console.error(error);
          }
        });
      },
      error: function(xhr, status, error) {
        // Handle any errors that occur during the AJAX request
        console.error(error);
      }
    });
  });

在控制台中，正如预期的那样，我得到了正确的结果，没有错误：

Country: Ukraine
ISO Code: UA
XHR finished loading: GET "https://mywebsite.com/wp-admin/admin-ajax.php?action=geoip_detect2_get_info_from_current_ip"
XHR finished loading: POST "https://mywebsite.com/wp-content/themes/theme_name/inc/product_layout/side_block.php".

然而，当我想在WordPress主题的PHP文件中输出结果时，我得到一个空结果：

$country = $_POST['country'];
$isoCode = $_POST['isoCode'];
echo "Country: " . $country . "<br>";
echo "ISO Code: " . $isoCode;

我做错了什么？
我使用的插件是geoip-detect。
服务器：Nginx php-fpm
Nginx日志中没有错误。