title: Add/update SEO metakeywords programmatically of woocommerce product
body: <p>Could you tell me please, what is the best way to add/update SEO metakeywords programmatically?</p>
  <p>i looked it up and found on this article how to update meta title and meta desc : <a href="https://ehikioya.com/how-to-update-yoast-seo-fields-programmatically/" rel="nofollow noreferrer">https://ehikioya.com/how-to-update-yoast-seo-fields-programmatically/</a></p>
  <p>when i tried to update the meta key words with the same code it wont work.</p>
  <pre><code>$updated_title = update_post_meta($post_id, ‘_yoast_wpseo_title’, $metatitle); //working
  $updated_desc = update_post_meta($post_id, ‘_yoast_wpseo_metadesc’, $metadesc); //working
  $updated_kw = update_post_meta($post_id, ‘_yoast_wpseo_metakeywords’, $metakeywords); // not working
  </code></pre>
  <p>I’m writing a plugin for import products and categories in WooCommerce.</p>