Check if customer bought product

functions.php

/**
 * Hide referral link/code if user hasn't purchased a specific product
 * 
 * @param bool $hide Current hide status
 * @param int $user_id Current user ID
 * @return bool Whether to hide the referral link
 */
add_filter('gens_raf_hide_referral_link', function($hide, $user_id) {
    // If already hidden, keep it hidden
    if ($hide) {
        return true;
    }
    
    // Product ID(s) that must be purchased to show referral link
    // Change this to your product ID or array of product IDs
    $required_product_ids = array(123); // Replace 123 with your product ID
    
    // Check if user has purchased any of the required products
    if ($user_id && function_exists('wc_customer_bought_product')) {
        $user = get_user_by('id', $user_id);
        
        if ($user) {
            foreach ($required_product_ids as $product_id) {
                if (wc_customer_bought_product($user->user_email, $user_id, $product_id)) {
                    return false; // User bought the product, show referral link
                }
            }
        }
    }
    
    // User hasn't purchased the required product, hide referral link
    return true;
}, 10, 2);