Shorten Your Post Titles through Wp show posts ?

Hi!
Need some advice to shorten titles on Wp Show Posts.
Found different ways here https://doc4design.com/wordpress-5ways-shorten-titles/ but not so sure :(

Saw kind of code like

<?php if (have_posts()) : while (have_posts()) : the_post(); ?>

<h1><?php the_title_limit( 30, ‘read more >’); ?></h1>

<?php endwhile; endif; ?>

But what's about the function in backoffice generated by the plugin itself ?
here : <?php if ( function_exists( 'wpsp_display' ) ) wpsp_display( 1746 ); ?>

Thanks!