You can use the objective explorer to export OKRs. Navigate to the objective explorer from the main menu. You may use the 'All objectives' view if you would like to export all your OKRs, or apply any desired filters, like time period or owner.
Please note that, by default, the objective explorer only displays top-level objectives. If you need the KRs, uncheck the box in the top-right.
Once your view is tweaked to your requirements, export it by clicking on Actions -> Export. You will receive an email with your download shortly. If you would like to learn more about the objective explorer, click here!