How to make custome search url

Hi WP experts!

The wordpress url search can be mysite.com/search/{query}. I’m trying very hard to find information how to create custom search to something like mysite.com/new-search-url/{query}.

I found a code in the internet

function custom_search_url( $search_rewrite ) {
if( !is_array( $search_rewrite ) ) { return $search_rewrite; }

$new_array = array();
foreach( $search_rewrite as $pattern => $s_query_string ) {
$new_array[ str_replace( 'search/', 'new-search-url/', $pattern ) ] = $s_query_string;
}
$search_rewrite = $new_array;
unset( $new_array );
return $search_rewrite;
}
add_filter("search_rewrite_rules", "custom_search_url");

They say put it into functions.php file in the theme. But it does not work.

Could anyone kindly help me how to do to have my custom search url?

Thank you in advance!