I created a new field in the checkout part using the a checkout field plugin. This field allows customer to specify a third email address outside of the billing or shipping address. I want to send the order confirmation only to this address and not to the billing part.
After several searches, I used Send Woocommerce Order to email address listed on product page answer code, replacing the order item meta key 'email'
by 'billing_email_guest'
like:
$email = wc_get_order_item_meta( $item_id, 'billing_email_guest', true );
But it doesn't work. What I am doing wrong?