Template Parts doesn’t work :/

Hi. I don’t know what i’m doing wrong in this tutorial, but i really can’t make it work:
https://displayposts.com/2019/01/04/use-template-parts-to-match-your-themes-styling/

This is my theme: https://ww.wp.xz.cn/themes/hueman/

And this is the theme structure:

hueman/
|__functions/
|__|__init-core.php
|__|__init-front.php
|__|__init-functions.php
|__|__more (…)
|__parts/
|__|__featured.php
|__|__header-main.php
|__|__page-title.php
|__|__more (…)
|__404.php
|__archive.php
|__comments.php
|__more (…)

1) I’ve created the template file “dps-gamebench.php” and put it on the folder “hueman > parts”;
2) In the section “Specify a layout in the shortcode”, on the official tutorial, i’ve copied the code and the only thing i’ve changed is the path “partials/dps” to “parts/dps”
3) i’ve tried paste and run this function in various php files in the folder “functions”. i’ve tried to use the plugin “Code Snippets” too, like the tutorial suggests, and none of this works!

Anyone can help me, please? There’s a way to debug this? What i’m missing out?