themes-wordpress/allez/templates/404.html

<!-- wp:template-part {"slug":"header","tagName":"header","align":"full"} /-->

<!-- wp:pattern {"slug":"allez/404" } /-->

<!-- wp:group {"style":{"spacing":{"margin":{"top":"0px","bottom":"0px"}}},"layout":{"type":"constrained"}} -->
<div class="wp-block-group" style="margin-top:0px;margin-bottom:0px"><!-- wp:template-part {"slug":"footer","tagName":"footer","align":"full"} /--></div>
<!-- /wp:group -->