public function add_alert_meta( $alert_meta, $alert_type ) {
        if ( $this->slug === $alert_type ) {
            $maker_key = wp_stream_filter_input( INPUT_POST, 'wp_stream_ifttt_maker_key' );
            if ( ! empty( $maker_key ) ) {
                $alert_meta['maker_key'] = $maker_key;