WordPress search form & results for custom post type

search.php

<?php
// check to see if there is a post type in the URL
if ( isset( $_GET['post_type'] ) && $_GET['post_type'] ):
	
	$filtered_posts = new WP_Query( array(
	    'post_type' => $_GET['post_type'],
	    'posts_per_page' => 12,
	    'orderby' => 'post_date',
	    's' => $_GET['s'],
	));

	if(have_posts($filtered_posts)):
		while(have_posts($filtered_posts)): the_post(); 
			$content = get_the_content();
			$excerpt = wp_trim_words(content, 22, '...');
		?>

		<div class="search-result-item">
			<a href="<?= get_the_permalink(); ?>"> 
				<h2> <?= get_the_title(); ?> </h2>
			</a>
			<div class="search-result-item__excerpt"> 
				<?= $excerpt ?>
			</div>
		</div>
	<?php			
		endwhile;
	else: 
		echo 'Sorry. We did not find any articles that match ' . $_GET['s'];
	endif;
endif;
?>

<!-- default search results code here -->

searchform-blogcovid.php

<form class="search" action="<?php echo home_url( '/' ); ?>">
  <input type="search" name="s" placeholder="Search&hellip;">
  <input type="submit" value="Search">
  <input type="hidden" name="post_type" value="blogcovid">
</form>