Why is add_action not working in wordpress plugin?

Question

WordPress

I'm trying to write a plugin so that the new customer of the Wocomer will receive an email notification
with his details and a discount coupon
, I can't get it to send a letter, the
letter generally sends normally
to another hook, I hang up, the letters reach
, but I don't understand how to make a new user receive a letter during registration why is
the plugin code not working

function new_customer_registered_send_email_admin($user_login) {
    $to = '[email protected]';  //EMAIL получателя
    $subject = 'тема письма'; //Тема письма
    $message = 'прошло'.$user_login; 
    wp_mail($to, $subject, $message);
}
add_action('new_customer_registered', 'new_customer_registered_send_email_admin');

in file /wp-content/themes/Avada/woocommerce/emails/customer-new-account.php
added

<?php do_action( 'new_customer_registered', $user_login ); ?>

without a plugin. registration letters also do not reach
others. at the same time, they normally arrive (new order, forgot the password, etc.)