Ordering an official transcript is done on the Registrar's office. While you're on their page, take some time to review the Registrar's Frequently Asked Questions about ordering a transcript.
IMPORTANT NOTE: If you have a hold on your record, you may not be able to order a transcript. To check if this is true for you, log into your My Buckeye Link account. If you see red circle with line through it at the top of the page, click it to learn more about the type of hold and its consequences.