Modify gift_message when adding a new order

[Nikola1337]

I am developing a carrier module which has multiple select options from which the user can choose from.I am saving his choice in the session, and I want to display his choice in the backend office, so when an employee views the order he knows which option the user has picked.
Here is my issue.Whenever I try to modify the order from the actionValidateOrder hook, no changes are actually applied to the order..

public function hookActionValidateOrder($params){
			
				$id_order = $params['order']->id;
				$id_carrier = $params['order']->id_carrier;
				
				if($id_carrier == Configuration::get(self::PREFIX . 'mycustomcarrier')){
					if (session_status() == PHP_SESSION_NONE) {
						session_start();
					}
					
					if(isset($_SESSION['mycustomcarrier'])){
						$params['order']->gift_message .= "User has picked .."; //you get the idea
					}
				}
			
		}

I am a rookie at developing prestashop modules, so feel free to share opinions or best practices approaching these the type of problem.

[catalin.pop]

I'm not sure if this is the best idea but I'll save values using

// save(update) value
Configuration::updateValue('my_module_something', 'some value'); 

// get value
Configuration::get('my_module_something'); // returns 'some value'

In your case for let's say order: #ASDFGS  I will save the value in json format like

{
  "param1":"zxcv",
  "param2":"qwer"
}

then read it from admin panel

// my_module = your module name
// ASDFGS = order reference id
Configuration::get('my_module_ASDFGS');