WordPress Agregue el HTML al contenido de Funcctoin.php
add_action('the_post', function($post, $query){
if(is_single()) {
echo "Test";
}
}, 10, 2);
Thankful Toad
add_action('the_post', function($post, $query){
if(is_single()) {
echo "Test";
}
}, 10, 2);