Show all members that has at least one active membership

code.php

<?php

add_shortcode( 'show_all_m2_members', 'show_all_m2_members' );
function show_all_m2_members() {
    $members = MS_Model_Member::get_members();
    $html = '<table>';
    $html .= '<tr>';
        $html .= '<th>Username</th>';
        $html .= '<th>Display name</th>';
    $html .= '</tr>';
    foreach( $members as $member ) {
        if( $member->has_membership() ) {
            $user = $member->get_user();
            $html .= '<tr>';
                $html .= '<td>';
                    $html .= $user->user_login;
                $html .= '</td>';
                $html .= '<td>';
                    $html .= $user->display_name;
                $html .= '</td>';
            $html .= '</tr>';
        }
    }
    $html .= '</table>';
    
    return $html;
}