Output php code to my page

Need to put a "<?php include (link) ?>" into one of my pages.
Tried all the passes at this link:
https://learn.getgrav.org/cookbook/plugin-recipes#how-do-i-inject-assets-like-javascript-and-css-files
creating the needed plugin with all the associated files.
Now what i get is just a "something" in my page, with my link remaining the same.
Help?
Thanks

No-one can help? I really can't figure it out....plugin seems working

Help with what? Which plugin is working? You need to rewrite your question and give much more information about what you want, what works and what doesn't work. Based on the current information you have given I don't think you can expect much help.

You cannot include PHP directly in your pages, but you need to make a little plugin

I followed the tutorial on getgrav site to integrate php in my page. I made the plugin, what i obtain is a "something" in my page. But whenever I try to incude php, nothing works. Seems like the plugin does nothing.