To get the TurboTax copy of your prior year online tax return you will have to wait until the 2018 online editions are available in December so that you can start a 2018 tax return and then upgrade and pay for the Plus edition so you can get access to the prior tax returns.
You can get free transcripts of a federal tax return, which will satisfy most lenders, from this IRS website - https://www.irs.gov/individuals/get-transcript
For a fee of $50 you can get a complete federal tax return from the IRS by completing Form 4506 - http://www.irs.gov/pub/irs-pdf/f4506.pdf
