Optional fee at checkout if certain categories are present in cart | woocommerce

optional-delivery-fee.php

<?php 

// add optional catering delivery fee to cart page IF catering product is in cart

add_action('woocommerce_cart_totals_after_shipping', 'lg_catering_delivery_info_at_cart');
function lg_catering_delivery_info_at_cart() {

	// set category check flag to be false until we find a product in that category
	$cat_check = false;
	// check each cart item for catering category
	foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
            
	    $product = $cart_item['data'];
	    
	    if ( has_term( 'catering', 'product_cat', $product->id ) ) {
	        $cat_check = true;
	        // break because we only need one "true" to matter here
	        break;
	    }
	}
	// if catering category is found, add optional delivery fee
	if ( $cat_check ) {
		global $woocommerce;
		    $product_id = 2090; // this is the delivery fee product
		foreach ( $woocommerce->cart->get_cart() as $cart_item_key => $values ) {
		    $_product = $values['data'];
		    if ( $_product->id == $product_id )
		        $found = true;
		    }
		    // if product not found, add it
		if ( ! $found ):
				?>
				<tr class="lg-delivery-fee">
			        <th>delivery available for <button onclick="document.getElementById('delivery-popup').style.display='block'"class="w3-button lg">downtown Raleigh only</button></th>
			        <td><a href="<?php echo do_shortcode('[add_to_cart_url id="2090"]'); ?>"><?php _e( 'add delivery fee (+$10)' ); ?> </a></td>
			    </tr>
				<div id="delivery-popup" class="w3-modal">
					<div class="w3-modal-content">
						<div class="w3-container">
							<span onclick="document.getElementById('delivery-popup').style.display='none'" class="w3-button w3-display-topright">&times;</span>
							<img src="http://lucettegrace.flywheelsites.com/wp-content/uploads/2018/04/DeliveryMap.jpg">
						</div>
					</div>
				</div>
						<?php else: ?>
		    <tr class="lg-delivery-fee">
		        <th><?php _e( 'delivery fee', 'woocommerce' ); ?></th>
		        <td>$10.00</td>
		    </tr>
		<?php endif;
		}

	}

?>

adapted from this stackexchange response