iTop/templates/base/components/form/layout.html.twig

<form method="post" enctype="multipart/form-data" id="{{ oUIBlock.GetId() }}"
      class="{{ oUIBlock.GetBlocksInheritanceCSSClassesAsString() }} {{ oUIBlock.GetAdditionalCSSClassesAsString() }} {% if oUIBlock.IsHidden() %}ibo-is-hidden{% endif %}"
      data-role="ibo-form"
        {% if oUIBlock.GetOnSubmitJsCode() %}
            onSubmit="{{ oUIBlock.GetOnSubmitJsCode() }}"
        {% endif %}
        {% if oUIBlock.GetAction() %}
            action="{{ oUIBlock.GetAction() }}"
        {% endif %}
        {% if oUIBlock.GetDataAttributes() %}
            {% for sName, sValue in oUIBlock.GetDataAttributes() %}
                data-{{ sName }}="{{ sValue }}"
            {% endfor %}
        {% endif %}
>
    {% block iboContentBlockContainer %}
        {% for oSubBlock in oUIBlock.GetSubBlocks() %}
            {{- render_block(oSubBlock, {aPage: aPage}) -}}
        {% endfor %}
    {% endblock %}
</form>