You can put this file into wp-content/mu-plugins folder.
See full details at https://gist.github.com/GeekPress/9d124b4694535454677fcebb2ee66b40
<?php if ( isset( $_GET['wc-ajax'] ) &amp;amp;&amp;amp; 'get_refreshed_fragments' === $_GET['wc-ajax'] &amp;amp;&amp;amp; ( !isset( $_COOKIE['woocommerce_cart_hash'] ) || empty( $_COOKIE['woocommerce_cart_hash'] ) ) &amp;amp;&amp;amp; ( !isset( $_COOKIE['woocommerce_items_in_cart'] ) || empty( $_COOKIE['woocommerce_items_in_cart'] ) ) ) { $data = get_transient( 'rocket_get_refreshed_fragments_cache' ); if ( ! empty( $data ) ) { $data = json_decode( $data ); wp_send_json( $data ); } ob_start(); add_action( 'shutdown', function() { set_transient( 'rocket_get_refreshed_fragments_cache', ob_get_clean(), 7 * DAY_IN_SECONDS ); }, 0 ); } // Delete the transient when the current theme is changed. add_action( 'switch_theme', function() { delete_transient( 'rocket_get_refreshed_fragments_cache' ); }, 0 );