Thank you for your response and sorry for my late 😉
So you mean, I can solve this like that:
function add_acf_body_class($class) {
$field = get_field_object('page_layout', get_queried_object_id());
$value = get_field('page_layout');
$label = $field['choices'][$value];
return $label;
}
add_filter('body_class', 'add_acf_body_class');
It’s a post. And nothing is added to the body class.