Step 1: Choose method: Google Drive. Then click Connect.

Step 2: Approve your account.

Because Order Exporter is under the review of Google to create a new app, you may get a screen like that. 

Don't worry, you can click Advanced and click Go to Ordersify: Order Exporter (unsafe) as normal

Step 3: Select a file you want to save.

Step 4: Click Save.