custom meta field for custom Taxonomies

class-mb-rest-api.php

function get_term_meta( $object ) {
        $output = array(); 
        if ( ! class_exists( 'MB_Term_Meta_Box' ) ) {
            return $output;
        }

var_dump( class_exists( 'MB_Term_Meta_Box' ) ) is false

and sure the term meta is enable