We don’t have this option,
If You use the kampina-child theme: You need to copy the folder
/kampina/includes/templates/related-posts/
into
/kampina-child/includes/templates/related-posts/
and edit index.php file:
Replace
$related_posts = kampina_get_related_posts();
with
$related_posts = kampina_get_related_posts( array( 'count_posts' => 10 ) );
If You use the kampina theme: only replace that line in the /kampina/includes/templates/related-posts/index.php
file.
But we recommended use child theme.
Best regards,
TigriWeb Team