wpd_ecommerce_checkout_email_subject_patient

/**
 * Change checkout email subject for patients
 */
function acme_checkout_email_subject_patient() {
    $email_subject_text = 'Thank you for your order.'; // Change this text.
    return $email_subject_text;
}
add_filter( 'wpd_ecommerce_checkout_email_subject_patient', 'acme_checkout_email_subject_patient' );