How do Include questions and answers in WordPress’s native search?

You can try add this code to functions.php or simply you can search in google for “include custom post type in wordpress search”. And then include ‘question’ and ‘answer’ post types.

<?php
add_filter( 'pre_get_posts', 'tgm_io_cpt_search' );
/**
 * This function modifies the main WordPress query to include an array of 
 * post types instead of the default 'post' post type.
 *
 * @param object $query  The original query.
 * @return object $query The amended query.
 */
function tgm_io_cpt_search( $query ) {
	
    if ( $query->is_search ) {
	$query->set( 'post_type', array( 'post', 'question', 'answer', 'any other post type you want' ) );
    }
    
    return $query;
    
}