How to display related posts according to Title and Category on a WordPress single page?

Here is my code: 

        <?php 
    $args = array(                          
        	'category__in' => $cat_id, // OK
                'posts_per_page' => 6,
                'post__not_in'   => array( get_the_ID() ),
                );
                    
        $wpex_query = new wp_query( $args );
    ?>

Note: Using category in query is OK. But I also want the Title in the query.