Use this code to replace the "@@@" placeholder in the "url" field with your affiliate network affiliate ID. [datafeedr]

replace-placeholder-with-affiliate-id-in-product-url.php

<?php

/**
 * Map each affiliate network ID to your affiliate ID for that network.
 *
 * In this example, Commission Junction's network ID is 3 and my Commission
 * Junction affiliate ID is '321321321'.
 */
$affiliate_ids = array(
	3  => '321321321',   // Commission Junction Affiliate ID.
	6  => '161493',      // ShareASale Affiliate ID.
	48 => 'VjUdjSOl*AJ', // Linkshare (Rakuten) Affiliate ID.
);

// Get the Affiliate Network ID from the $product array.
$network_id = $product['source_id'];

// Get the product's affiliate link URL from the $product array.
$product_url = $product['url'];

// Get the proper affiliate ID for this product's affiliate network.
$affiliate_id = $affiliate_ids[ $network_id ];

// Replace the "@@@" placeholder with your affiliate ID.
$affiliate_link = str_replace( '@@@', $affiliate_id, $product_url );

// Display the affiliate link.
echo '<a href="' . $affiliate_link . '">Buy Now</a>';