Filter to put more classes in the body class function, in the example below you are adding the "post slug"

body-classes-plus.php

<?php
/*
* Filtro para colocar mais classes na função body class, no exmeplo abaixo está adicionando o "slug do post"
*/
add_filter('body_class', 'body_classes_plus');

function body_classes_plus($classes) {
	global $post;
    
    $classes[] = (!is_home()) ? $post->post_name : ''; // Slug do post
    //$classes[] = 'anything else';
    return $classes;
}