GCloud platform provides object storage service, which can be managed from "Object Storage" leftside menu as shown in Img. 1
To get access to object storage service, first you need to register to this service. You can do it from "Manage" tab in Object Storage section as show in Img. 2. Click on "Register" button and also pay attention to object storage service address shown on this page.
After registering, you will get access to those keys, which is used for object storage service. Click on "Download Keys" button to store these keys to your local computer. (Img. 3)
You can review your object storage capacity and total stored amount in "Usage" tab (Img. 4) as well as the fee which was charged for object storage usage.