sylvieH-3

<wpml-config>
  <gutenberg-blocks>
    <gutenberg-block type="stackable/video-popup" translate="1">
      <key name="videoLink"></key>
      <xpath type="link">//div/@data-video</xpath>
    </gutenberg-block>
  </gutenberg-blocks>
</wpml-config>

After that, update the page in the default language and its translation.

<strong>Relevant Documentation:</strong>
https://wpml.org/documentation/support/language-configuration-files/