Capacitor.config.ts change plugin config based on platform

I have noticed that when I run ionic cap sync (or update or copy), ionic-cli will read the file /capacitor.config.ts and generate a json file for Android and another for iOS.

I need to change the configuration of the PushNotifications plugin depending on the platform, but although I can read the process.env variable from the capacitor.config.ts file I have not seen how to check if the current platform being generated is either Android or iOS.

Is this possible or am I approaching this the wrong way?