Select the Google Cloud option from the list of providers. If you haven't already configured credentials for Google Cloud you'll be asked to provide them now. Enter a name for your credentials then click Upload file and select your JSON private key. Once this is done, click Save.
Once you have added your credentials (or if you already had them set up) select your cluster options from the fields below.
You can also expand the More settings section and set groups and tags for your environment now or you can do this later.
Once you have made your selections, click Provision environment to begin the provision. If you have other environments to configure click Next to proceed, otherwise click Close to return to the list of environments where you will see the progress of your provision.