If you completed Form 1040X and want to print to mail it then please follow these instructions:
Please log back in your TurboTax account and "add a state" to open the return back up (you are not really adding a state, just to open it back up), then select Tools on the left, Print Center and choose the print center, then select returns and choose to print just the tax return or to include all worksheets as well.
Otherwise please review how to amend your tax return:
https://ttlc.intuit.com/replies/3288565