How to find Google Storage keys
To get the Access and Secret keys go to Google Storage for Developers website and click Activate Google Storage button. it is kind of weird that you have to click it every time even though you have activated Google Storage before
Scroll down to Google APIs Console at the left side navigation and click on it. this will get you to the APIs console. Now click Legacy Access and you will see the keys in the list. Just copy Access and Secret keys to the form above. See the screen below.