How make custom order fields required with "event_define_rules" like a required address fields?

Question

I want to make a craft commerce custom order field required (server side). I already use this for require the default address fields. But how to add custom fields? Because this is done on the Address class.

        /**
         * Server require custom order fields
         */
        Event::on(
          Address::class,
          Model::EVENT_DEFINE_RULES,
          function(DefineRulesEvent $event) {
              $rules = $event->rules;
              $rules[] = [['firstName', 'lastName'], 'required'];
              $rules[] = ['field:fieldHandle', 'required']; // <- this is not working
              $event->rules = $rules;
          }
        );