A Unity ID allows you to buy and/or subscribe to Unity products and services, shop in the Asset Store and participate in the Unity community.
Separate names with a comma.
You can put your list in a class and use JSONSerialization to convert your class to json and save it that way...
You can check if serialized field is null in awake and throw and exception. It doesn't prevent playing the game but displays an red error message...
January 2023 and still exists