meta_box.php

<?php

/*******************************************************************************
Add Centre meta box to the facilities - Centre plugin - facilities Post Type
*******************************************************************************/
if(!function_exists('add_bwm_facilities_centre_meta_box'))
{
    function add_bwm_facilities_centre_meta_box()
    {

        add_meta_box("bwm_facilities_centre_meta_box", "BWM Cenres Content Override", "bwm_facilities_centre_meta_box_markup", array("facilities"), "normal", "high", null);

        $vc = new Vc_Backend_Editor();
        $vc->registerBackendJavascript();
        $vc->registerBackendCss();
        $vc->post = $post;
        // B.C:
        visual_composer()->registerAdminCss();
        visual_composer()->registerAdminJavascript();

        // meta box to render
        add_meta_box(
            'test_wpb_visual_composer',
            __( 'test WPBakery Page Builder', 'test_js_composer' ),
            array($vc,'renderEditor'),
            array("facilities"),
            'normal',
            'high'
        );


    }
    add_action("add_meta_boxes", "add_bwm_facilities_centre_meta_box");
}