Display SKU on WC Cart PDF table

cart-table.php

<?php
/**
 * WC Cart PDF template
 * 
 * @package wc-cart-pdf
 */

/**
 * Before template hook
 *
 * @since 1.0.4
 */
do_action( 'wc_cart_pdf_before_template' );

$logo = parse_url( get_option( 'wc_cart_pdf_logo', get_option( 'woocommerce_email_header_image' ) ), PHP_URL_PATH );
$logo = ! $logo ? '' : $_SERVER['DOCUMENT_ROOT'] . $logo;
?>

<div id="template_header_image">
    <?php
        if ( file_exists( $logo ) ) {
            printf( '<p style="margin-top: 0; text-align: %s;"><img src="%s" style="width: %s;" alt="%s" /></p>',
                get_option( 'wc_cart_pdf_logo_alignment', 'center' ),
                esc_url( $logo ),
                get_option( 'wc_cart_pdf_logo_width' ) ? get_option( 'wc_cart_pdf_logo_width' ) . 'px' : 'auto',
                get_bloginfo( 'name', 'display' )
            );
        }
    ?>
</div>
<table class="shop_table shop_table_responsive cart woocommerce-cart-form__contents" cellspacing="0">
    <thead>
        <tr>
            <th class="product-thumbnail">&nbsp;</th>
            <th class="product-name"><?php esc_html_e( 'Product', 'woocommerce' ); ?></th>
            <th class="product-sku"><?php esc_html_e( 'SKU', 'woocommerce' ); ?></th>
            <th class="product-price"><?php esc_html_e( 'Price', 'woocommerce' ); ?></th>
            <th class="product-quantity"><?php esc_html_e( 'Quantity', 'woocommerce' ); ?></th>
            <th class="product-subtotal"><?php esc_html_e( 'Total', 'woocommerce' ); ?></th>
        </tr>
    </thead>
    <tbody>
        <?php
        foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
            $_product   = apply_filters( 'woocommerce_cart_item_product', $cart_item['data'], $cart_item, $cart_item_key );
            $product_id = apply_filters( 'woocommerce_cart_item_product_id', $cart_item['product_id'], $cart_item, $cart_item_key );

            if ( $_product && $_product->exists() && $cart_item['quantity'] > 0 && apply_filters( 'woocommerce_cart_item_visible', true, $cart_item, $cart_item_key ) ) {
                $product_permalink = apply_filters( 'woocommerce_cart_item_permalink', $_product->is_visible() ? $_product->get_permalink( $cart_item ) : '', $cart_item, $cart_item_key );
                ?>
                <tr class="woocommerce-cart-form__cart-item <?php echo esc_attr( apply_filters( 'woocommerce_cart_item_class', 'cart_item', $cart_item, $cart_item_key ) ); ?>">

                    <td class="product-thumbnail">
                    <?php
                    $thumbnail = apply_filters( 'woocommerce_cart_item_thumbnail', $_product->get_image( 'woocommerce_thumbnail', array( 'width' => 60, 'height' => 'auto' ) ), $cart_item, $cart_item_key );

                    if ( ! $product_permalink ) {
                        echo $thumbnail; // PHPCS: XSS ok.
                    } else {
                        printf( '<a href="%s">%s</a>', esc_url( $product_permalink ), $thumbnail ); // PHPCS: XSS ok.
                    }
                    ?>
                    </td>

                    <td class="product-name" data-title="<?php esc_attr_e( 'Product', 'woocommerce' ); ?>">
                    <?php
                    if ( ! $product_permalink ) {
                        echo wp_kses_post( apply_filters( 'woocommerce_cart_item_name', $_product->get_name(), $cart_item, $cart_item_key ) . '&nbsp;' );
                    } else {
                        echo wp_kses_post( apply_filters( 'woocommerce_cart_item_name', sprintf( '<a href="%s">%s</a>', esc_url( $product_permalink ), $_product->get_name() ), $cart_item, $cart_item_key ) );
                    }

                    do_action( 'woocommerce_after_cart_item_name', $cart_item, $cart_item_key );

                    // Meta data.
                    echo wc_get_formatted_cart_item_data( $cart_item ); // PHPCS: XSS ok.

                    // Backorder notification.
                    if ( $_product->backorders_require_notification() && $_product->is_on_backorder( $cart_item['quantity'] ) ) {
                        echo wp_kses_post( apply_filters( 'woocommerce_cart_item_backorder_notification', '<p class="backorder_notification">' . esc_html__( 'Available on backorder', 'woocommerce' ) . '</p>', $product_id ) );
                    }
                    ?>
                    </td>

                    <td class="product-sku" data-title="<?php esc_attr_e( 'SKU', 'woocommerce' ); ?>">
                      <?php echo esc_html( $_product->get_sku() ); ?>
                    </td>

                    <td class="product-price" data-title="<?php esc_attr_e( 'Price', 'woocommerce' ); ?>">
                        <?php
							echo apply_filters( 'woocommerce_cart_item_price', WC()->cart->get_product_price( $_product ), $cart_item, $cart_item_key ); // PHPCS: XSS ok.
						?>
                    </td>

                    <td class="product-quantity" data-title="<?php esc_attr_e( 'Quantity', 'woocommerce' ); ?>">
                        <?php print esc_html( $cart_item['quantity'] ); ?>
                    </td>

                    <td class="product-subtotal" data-title="<?php esc_attr_e( 'Total', 'woocommerce' ); ?>">
                        <?php
							echo apply_filters( 'woocommerce_cart_item_subtotal', WC()->cart->get_product_subtotal( $_product, $cart_item['quantity'] ), $cart_item, $cart_item_key ); // PHPCS: XSS ok.
						?>
                    </td>
                </tr>
                <?php
            }
        }
        ?>

        <tr class="cart-subtotal cart-total-row">
			<th class="row-subtotal" colspan="4" style="text-align: right;"><?php _e( 'Subtotal', 'woocommerce' ); ?></th>
			<td class="row-subtotal" data-title="<?php esc_attr_e( 'Subtotal', 'woocommerce' ); ?>"><?php wc_cart_totals_subtotal_html(); ?></td>
        </tr>
        
        <?php if ( 0 < WC()->cart->get_shipping_total() ) : ?>
            <tr class="shipping cart-total-row">
                <th class="row-subtotal" colspan="4" style="text-align: right;"><?php _e( 'Shipping', 'woocommerce' ); ?></th>
                <td class="row-subtotal" data-title="<?php esc_attr_e( 'Shipping', 'woocommerce' ); ?>"><?php echo WC()->cart->get_cart_shipping_total(); ?></td>
            </tr>
        <?php endif; ?>

        <?php foreach ( WC()->cart->get_coupons() as $code => $coupon ) : ?>
			<tr class="cart-discount coupon-<?php echo esc_attr( sanitize_title( $code ) ); ?> cart-total-row">
				<th class="row-coupon" colspan="4" style="text-align: right;"><?php wc_cart_totals_coupon_label( $coupon ); ?></th>
				<td class="row-coupon" data-title="<?php echo esc_attr( wc_cart_totals_coupon_label( $coupon, false ) ); ?>"><?php wc_cart_totals_coupon_html( $coupon ); ?></td>
			</tr>
		<?php endforeach; ?>

        <?php foreach ( WC()->cart->get_fees() as $fee ) : ?>
			<tr class="fee cart-total-row">
				<th class="row-subtotal" colspan="4" style="text-align: right;"><?php echo esc_html( $fee->name ); ?></th>
				<td class="row-subtotal" data-title="<?php echo esc_attr( $fee->name ); ?>"><?php wc_cart_totals_fee_html( $fee ); ?></td>
			</tr>
		<?php endforeach; ?>

		<?php if ( wc_tax_enabled() && ! WC()->cart->display_prices_including_tax() ) :
			$taxable_address = WC()->customer->get_taxable_address();
			$estimated_text  = WC()->customer->is_customer_outside_base() && ! WC()->customer->has_calculated_shipping()
					? sprintf( ' <small>' . __( '(estimated for %s)', 'woocommerce' ) . '</small>', WC()->countries->estimated_for_prefix( $taxable_address[0] ) . WC()->countries->countries[ $taxable_address[0] ] )
					: '';

			if ( 'itemized' === get_option( 'woocommerce_tax_total_display' ) ) : ?>
				<?php foreach ( WC()->cart->get_tax_totals() as $code => $tax ) : ?>
					<tr class="tax-rate tax-rate-<?php echo sanitize_title( $code ); ?> cart-total-row">
						<th class="row-subtotal" colspan="4" style="text-align: right;"><?php echo esc_html( $tax->label ) . $estimated_text; ?></th>
						<td class="row-subtotal" data-title="<?php echo esc_attr( $tax->label ); ?>"><?php echo wp_kses_post( $tax->formatted_amount ); ?></td>
					</tr>
				<?php endforeach; ?>
			<?php else : ?>
				<tr class="tax-total cart-total-row">
					<th class="row-subtotal" colspan="4" style="text-align: right;"><?php echo esc_html( WC()->countries->tax_or_vat() ) . $estimated_text; ?></th>
					<td class="row-subtotal" data-title="<?php echo esc_attr( WC()->countries->tax_or_vat() ); ?>"><?php wc_cart_totals_taxes_total_html(); ?></td>
				</tr>
			<?php endif; ?>
		<?php endif; ?>

		<?php do_action( 'woocommerce_cart_totals_before_order_total' ); ?>

        <tr class="order-total cart-total-row">
			<th class="row-subtotal" colspan="4" style="text-align: right;"><?php _e( 'Total', 'woocommerce' ); ?></th>
			<td class="row-subtotal" data-title="<?php esc_attr_e( 'Total', 'woocommerce' ); ?>"><?php wc_cart_totals_order_total_html(); ?></td>
		</tr>

		<?php do_action( 'woocommerce_cart_totals_after_order_total' ); ?>
    </tbody>
</table>
<div id="template_footer">
    <?php echo wpautop( wp_kses_post( wptexturize( apply_filters( 'woocommerce_email_footer_text', get_option( 'woocommerce_email_footer_text' ) ) ) ) ); ?>
</div>

<?php
/**
 * After template hook
 *
 * @since 1.0.4
 */
do_action( 'wc_cart_pdf_after_template' );