Makes the Gift Aid checkbox to be checked by default

default-gift-aid-to-yes.php

<?php
function gift_aid_default_checked() { ?>
	<script>
        jQuery("input[name=give_gift_aid_accept_term_condition]").prop("checked", true);

	</script>

<?php }

add_action( 'give_donation_form_after_submit', 'gift_aid_default_checked' );