There should be a Cancel Amend in the left menu.
Otherwise, cancel by deleting Form 1040-X for the federal and the corresponding amended return for any state filing.
To see these forms, follow these steps:
- From the left menu, select Tax Tools.
- Select Tools.
- Scroll to Delete a Form.
- Scroll to Form 1040-X and select Delete and Delete Selected Form and Continue.
- Scroll to the state section and scan for the amended return form.
- Scroll to the bottom of the next window and select Continue With My Return.
For more information, see: Do I need to amend?