The extension is form 4868. It should be part of your tax return. In addition, if you made a payment by April 15th online, you would have marked it as part of your extension. Check your records for payments as well. The payment counts as an extension request if you don't have the 4868 and properly marked the payment.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"