Do i need to write my own Plugin to get $_GET-Param?

Hello there!
Until know, i enjoyed grav much, but now im stuck. I need a $_GET param in one of my sides. First, i tried to get it by using the twig app.request.query.get("opt"). This always returned "null". I searched this forum and found that someone wanted to write his own plugin to read this variable.

Unfortunally he didn't seem to finish nor publish this plugin. Do i really need a plugin for "just" getting $_GET and $_POST params and if so, what is the easiest way?

Greetings,
RastaTux

You can already use get parameters with the Grav uri object:
https://learn.getgrav.org/themes/theme-vars#uri-object

Ah nice, thank you! I didn't find this page, sorry.