Limits the ZIP Code field for 5 digits only

limit-zip-code-size.php

<?php
function my_give_limit_zip_length() { ?>

    <script>
		let zipcodes = document.querySelectorAll('input#card_zip');
		zipcodes.forEach(zipcode => zipcode.setAttribute('maxlength', 5));
    </script>

<?php }

add_action( 'give_donation_form_after_submit', 'my_give_limit_zip_length' );