Download the ACF – Gravity Forms Field from GitHub.

Then use this code or something similar:

$related_appeal_form = get_field('related_appeal_form');
//var_dump_formatted($related_appeal_form);
gravity_form_enqueue_scripts($related_appeal_form->id, true);
echo '
<h2 class="feature_title">Donate now to help secure South Australia\'s heritage:</h2>
';
gravity_form($related_appeal_form->id, $display_title=false, $display_description=false, $display_inactive=false, $field_values=null, $ajax=false, $tabindex=999);