Platform specific API Keys for React Native Setup

Link to original RC doc: https://www.revenuecat.com/docs/configuring-sdk

For the React Native Setup, it mentions the api keys (for Apple and Android).

Code in the documentation:

if (Platform.OS === 'ios') {

  Purchases.configure({apiKey: <public_ios_sdk_key>});

} else if (Platform.OS === 'android') {

  Purchases.configure({apiKey: <public_google_sdk_key>});

}

What are these sdk keys exactly? Is it the App Connect Key or the Issuer Id? I searched the documentation and could not find more info.