Meta Box

Hi I have my meta boxes working in the back end with all my custom fields. But I just bought the front end submissions plugin and have written my code below. The problem is it just echo's the string onto the page and doesn't put out the front end form. The code is giving me all the right fields in the admin end of wordpress. But trying to use it in the front end, it just echo's the string. And I have added my license key to the updater.

My php Shortcode

<?php  
    $form = '[mb_frontend_form id="deposit_price"]';
    echo do_shortcode( $form );
?>

My php Meta Box Code

function add_meta_fields( $meta_boxes ) {
        $meta_boxes[] = array(
          'id' => 'deposit_price',
          'title' => 'Finance' ,
          'post_types' => array('rentals'),
          'context' => 'normal',
          'autosave' => false,
          'fields' => array(
            array(
                'id' => 'deposit_price_field',
                'type' => 'number',
                'name' => 'Deposit',
                'placeholder' => 'Just the number : 123456',
            ),
          ),
        );
    return $meta_boxes;
  }
add_filter( 'rwmb_meta_boxes', 'add_meta_fields' );