Snippets for https://hookturn.io/advanced-forms-for-acf-version-1-9-3-2-released/

af-field-group-wrapper-hooks.php

<?php

add_action( 'af/field_group/before_field_group', function ( $field_group, $form, $args ) {

	if ( $form['key'] !== 'form_64c0bb30bd954' ) {
		return;
	}

	echo '<div class="my-field-group-wrapper">';

}, 10, 3 );

add_action( 'af/field_group/after_field_group', function ( $field_group, $form, $args ) {

	if ( $form['key'] !== 'form_64c0bb30bd954' ) {
		return;
	}

	echo '</div>'; // eof .my-field-group-wrapper

}, 10, 3 );