How to Add to Cart Quantity Input Suffix in WooCommerce Single Product Page

Use this code:

add_action( 'woocommerce_after_quantity_input_field', 'wtwh_echo_qty_front_add_cart' );
function wtwh_echo_qty_front_add_cart() {
echo '<span class="qty-suff">Qty</span>';
}

How do you add it to the checkout page too?

1. There will be no signup or registration page on the website
2. The website will have only courses daily classes and log in page.
3. Students can view course content only by logging in.
4. Students can login with their mobile number. I will save the students' mobile number in the back end of WordPress so that the student can login with that number.
5. No one can view the course content without logging in
Sir please help me thank you very much ❤❤

Excellent 👍