Next and previous link in new post type

Hello, I am using this code for shortcode

$nextPost = get_next_post(true);
 $nextURL = get_permalink($nextPost->ID);
echo '<a class="next-product" href="';
echo $nextURL;
echo '">></a>';

It is working for POST in SAME category. How can I change it so that it works for other POST TYPES – For example PAGE or some new post type – f.e. FOTOGRAFIE. within its own TAXONOMY

Thanks
Jan