The option that controls when UnityWebRequest can use plain text HTTP connections.
The default value is InsecureHttpOption.NotAllowed, because plain text HTTP connections are not secure and can make your application vulnerable to security threats.
This property corresponds to Allow downloads over HTTP in the Configuration group of Other Settings in the Player settings, and applies to every platform in the project. Unity applies the value that the project has when you build the player.
For more information about the available options, refer to InsecureHttpOption.
Additional resources: InsecureHttpOption, Player settings.