I'm trying to set a script to inactive

So I have a game built for Android and iOS. I want to also now build it for facebook. But my Ads scripts are currently only for android and iOS. the error I’m getting is

 gameID does not exist in current context

because those game IDs are for unity ads on android and iOS.
I don’t want to delete the scripts just to be able to publish to facebook. is there a way or method to say if android and iOS are not here return? The current script I have for checking the gameID for android and iOS is.

     private string gameID = "xxxxxxxxx";
     private string gameID = "xxxxxxxxx";

Well since the ads script is only for android and ios, you could just put the entire contents of the scripts in a #if UNITY_IOS || UNITY_ANDROID check, or you could have an else with just the gameID as an empty string.