Flux checkout - show notice "Get 20% off when purchasing 2"

functions.php

<?php
add_action( 'woocommerce_review_order_before_cart_contents', 'flux_display_display_notice_to_get_discount_with_qty', 10 );
function flux_display_display_notice_to_get_discount_with_qty() {
	$current   = WC()->cart->cart_contents_count;
	$return_to =  wc_get_page_permalink( 'shop' );

	echo '<tr><td colspan="2">';
	switch ( $current ) {
		case '1':
			$added_text = 'Get 20% off when purchasing 2!';
			$notice     = sprintf( '<a href="%s" class="button wc-forward">%s</a> %s', esc_url( $return_to ), '', $added_text );
			wc_print_notice( $notice, 'notice' );
			break;

		case '2':
			$added_text = 'Get 30% off when purchasing 3!';
			$notice     = sprintf( '<a href="%s" class="button wc-forward">%s</a> %s', esc_url( $return_to ), '', $added_text );
			wc_print_notice( $notice, 'notice' );
			break;
	}

	echo '</td></tr>';
}