Untitled

add_action('marketking_order_statuses_custom', function($vendor_id, $status){
	?>
	<option value="custom_status" <?php selected($status, 'custom_status', true);?>>Custom Status</option>
	<?php
}, 10, 2);
add_filter('marketking_all_order_statuses_modifiable','__return_true');
add_filter('marketking_custom_status_text', function($text, $status){
	if ($status === 'custom_status'){
		$text = 'Custom Status';
	}
	return $text;
}, 10, 2);