core/Fields/Definitions/templates/gallery-ext/default.twig
{% extends Form.getLayout() %}
{% block fieldmarkup %}
<div id='{{ Form.getInputFieldId() }}' data-fieldkey='{{ Field.getKey() }}'
data-arraykey='{{ Field.getArg('arrayKey') }}' data-module='{{ Field.getFieldId() }}'
class='kb-gallery-ext__stage'>
<input type="hidden" name="{{ Field.getFieldId() }}[{{ Field.getKey() }}][present]" value="yes">
</div>
{% endblock %}