Use the <a href="https://github.com/wikimedia/composer-merge-plugin">Composer Merge plugin</a> to include the Webform module's <a href="https://cgit.drupalcode.org/webform/tree/composer.libraries.json">composer.libraries.json</a> or generate a custom file using <code>drush @webform-libraries-composer &gt; DRUPAL_ROOT/composer.libraries.json</code>.