Welcome to the guide on Configuring the CURLOPT_HTTP_VERSION in the MailChimp for WooCommerce Integration. This guide will help you understand how to select a specific HTTP protocol version when using PHP CURL.

At times, your server might require a specific HTTP protocol version when using PHP CURL. By default, the plugin uses CURL_HTTP_VERSION_1_1, but you have the option to select any valid CURL setting. For more details on valid settings, you can refer to the official CURL documentation.

To specify a different HTTP version, follow these steps:

1. Open your wp-config.php file.
2. Add the following line of code to define the desired HTTP version:

define('MAILCHIMP_USE_HTTP_VERSION', CURL_HTTP_VERSION_1_1);

By adding this to your wp-config.php file, you will override the default setting provided by the plugin.