Woocommerce在选择送货方式时有条件地显示电子邮件文本

I am editing the Woocommerce E-Mail template of customer-processing-order.php in my Child-Theme to show a E-Mail text conditionally when a shipping method is selcted. In my case it is when this Shipping method got selected:

<input type="radio" name="shipping_method_[0]" data-index="0" id="shipping_method_0_23568" value="23568" class="shipping_method">

The Code below is what I have but it is always just showing the else sentence. Is the shipping method id wrong? I have tried already also "shipping_method_0_23568" but it does always just show the else sentence.

<?php
$shipping_method_arr = get_post_meta($order_id, '_shipping_method', false); // an array
$method_id = explode( ':', $shipping_method_arr[0][0] );
$method_id = $method_id[0];  // We get the slug type method


if ( '23568' == $method_id ){
    echo 'if sentence...';
} elseif ( '23569' == $method_id ){
    echo 'elseif sentence....';
} else {
    echo 'else sentence...';
}
?>

Can someone help me with that? Thank you!