How to create plugin with shopkeeper3 method call in modx Revo?

Question

MODX

Hi people.
Full question:
I have shopkeeper3, modx REVO. For products, the price depends on the option chosen. (1l - 100 r, 2l - 200 r, 3l - 300 r..). I found the answer like this, but I don’t have enough experience to understand what exactly, how and where to do it:

Создаем плагин itemPrice
текст:
<?php
$output = 0;
if(!empty($_POST['itemPrice']) && is_numeric($_POST['itemPrice'])){
$output = $_POST['itemPrice'];
}else{
$output = $modx->getOption('price',$scriptProperties,0);
}
$modx->event->_output = '';
$modx->event->output($output);
return '';

Выбираем для плагина системное событие "OnSHKgetProductPrice"

How and where to create a plugin and how to call the "OnSHKgetProductPrice" method. As I understand it, this plugin will change the price of the product depending on the option and send it to the cart. Just what I need. On the product page itself, I made the price change dynamically in the field in js when the corresponding checkbox is selected. But the price is not transferred to the basket, there is always 0 rubles.

Answer 1

in your admin panel, go to /manager/?a=element/plugin/create&category=0
, give an arbitrary name, in the "system events" tab, look for and mark "OnSHKgetProductPrice".
Paste your code into the text of the plugin and save it.
Your plugin should work.