<div class="form-check">
<input type="checkbox"
       name="${field.name}"
       value="${field.widget.true_val}"
       id="${field.oid}"
       class="${field.widget.css_class}${' is-invalid' if field.error else ''}"
       tal:attributes="checked cstruct==field.widget.true_val">
<label tal:condition="field.widget.title" for="${field.oid}" tal:content="structure field.widget.title"></label>
</div>