How to direct a user to the full-form create on a subpanel

fullFormCreateContacts.php

<?php

    $layout_defs["Accounts"]["subpanel_setup"]["contacts"]["top_buttons"] = array(
        array(
            'widget_class' => 'SubPanelTopCreateButton',
        ),
        array(
            'widget_class' => 'SubPanelTopSelectButton',
            'mode' => 'MultiSelect',
        ),
    );