The apply
control saves your settings. You can set the reload
control property to true in order to trigger a builder reload after the “Apply” button has been clicked. We use it in the builder for settings like the template “Populate Content” or the “SEO” page settings.
$this->controls['apply'] = [
'group' => 'template-preview',
'type' => 'apply',
'reload' => true,
'label' => esc_html__( 'Apply preview', 'bricks' ),
];