Setting Google Public Key
It is possible to set the Google Public Key in two different places either in the Unity Editor or in the Project Setting in the dashboard.
In Unity Editor
- Follow the steps in Getting Started Guide to go to the In-App Purchasing service window
- Follow the steps to enter the Google Public Key in the Optionssection of the In-App Purchasing service window 
In project dashboard
- Go to the Unity Dashboard
- Open the left menu and select SettingsthenProject SettingsunderProject and select the project and select the project
- In the section In-app purchase (IAP) settingsedit the fieldGoogle License Key