functions.php

add_action( 'woocommerce_cart_coupon', 'woocommerce_empty_cart_button' );
function woocommerce_empty_cart_button() {
	echo '<a href="' . esc_url( add_query_arg( 'empty_cart', 'yes' ) ) . '" class="button" title="' . esc_attr( 'Empty Cart', 'woocommerce' ) . '">' . esc_html( 'Empty Cart', 'woocommerce' ) . '</a>';
}