IntlDateTime | extented version of php 5 DateTime class | Internationalization library

  // in EmailOrderConfirmation --nova action
  // declare what you are using
  // use Illuminate\Support\Facades\Mail;
  // use App\Mail\ResendOrder;
  
  public function handle(ActionFields $fields, Collection $models)
  {
        //loop over the orders that have been selected in nova
        foreach ($models as $order) {
            $contact = $order->contract; //however you are getting contract data
            //assuming you have a $order->user  order belongs to user relationship
            //send mail to the user, with the order/contract details to create your email
            Mail::to($order->user->email)->send(new ResendOrder($contact));
        }
        //return a message to nova
        return Action::message('Mail envoyé');
    }

    // in  Order /Nova resource
    // declare what you are using
    // use App\Nova\Actions\EmailOrderConfirmation;
      
    public function actions(Request $request)
    {
        return [new EmailOrderConfirmation];
    }