function custom_quiz_completed( $data, $user ) {

    if ( ! function_exists( 'wp_fusion' ) ) {
        return;
    }

    if ( $data['pass'] == false ) {

        if ( wp_fusion()->user->has_tag( 'COURSE FAILED - CINV M1' ) ) {

            $tag_id = wp_fusion()->user->get_tag_id( 'Quiz Fail 1' );

            wp_fusion()->user->apply_tags( array( $tag_id ) );

        }

    }

}

add_action( 'learndash_quiz_completed', 'custom_quiz_completed', 5, 2 );