function wpdc_custom_check_user_membership( $user_id, $user ) {
    if ( ! wp_fusion()->user->has_tag( 'active-member', $user_id  ) {
        wp_safe_redirect( home_url() );
        exit;
    }
}

add_action( 'wpdc_sso_provider_before_sso_redirect', 'wpdc_custom_check_user_membership', 10, 2 );