Google Merchant Sync: Authorize your Google account with WooCommerce Shop
The "Save" the setting.
Then you will see:
If you are not authorize, please click "Authenticate Now"
See the changes on each feed:
When you authorized your shop, at the Feed, you will see:
Click at "Send to Google Merchant" to let you upload directly your product feeds on Google Shopping account or Google Adwords. If you want to take products feed to your facebook or Pinterest, you can click at "Save & Generate Feed"