AutomateWoo - Async custom trigger example

functions.php

<?php
     
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

// Register AutomateWoo triggers.
add_filter( 'automatewoo/triggers', function ( $triggers ) {
	// Include the file containing the trigger class
	require_once 'my-custom-order-paid-trigger.php';

	// Add the trigger to the $triggers array
	// Set a unique name for the trigger and then the class name
	$triggers['my_custom_order_paid_trigger'] = 'My_Custom_Order_Paid_Trigger';

	return $triggers;
} );

my-custom-order-paid-trigger.php

<?php

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Class My_Custom_Order_Paid_Trigger
 */
class My_Custom_Order_Paid_Trigger extends \AutomateWoo\Trigger {

	/**
	 * Async events required by the trigger.
	 *
	 * Since we are using the `automatewoo/order/paid_async` action we must require the `order_paid` event.
	 *
	 * @var string|array
	 */
	protected $required_async_events = 'order_paid';

	/**
	 * Load trigger admin details.
	 */
	public function load_admin_details() {
		$this->title       = __( 'Order Paid Custom Version', 'automatewoo' );
		$this->description = __( 'This is trigger uses the async order paid event.', 'automatewoo' );
	}

	/**
	 * Register trigger's hooks.
	 */
	public function register_hooks() {
		add_action( 'automatewoo/order/paid_async', [ $this, 'handle_trigger_event' ] );
	}

	/**
	 * Callback for async order paid trigger event.
	 *
	 * @param int $order_id
	 */
	public function handle_trigger_event( $order_id ) {
		$order = wc_get_order( $order_id );

		if ( ! $order ) {
			return;
		}

		// Attempt to run any workflows that are using this trigger.
		$this->maybe_run(
			array(
				'order'    => $order,
				'customer' => \AutomateWoo\Customer_Factory::get_by_order( $order ),
			)
		);
	}

}

This looks fairly easy, but I’m struggling because I’m not a coder. Where should we create the php custom trigger file? Inside the child theme I suppose? I’m using Woocommerce Order Status Manager and would like to add custom triggers for sending emails using Automatewoo.
Thanks!