You originally posted "I sold a home in 2017 and didn't receive a 1099-S form from the IRS to report gross proceeds."
If you sold your primary personal residence and you lived in and owned the home for at least two years in the five year period on the date of sale, you do not have to report the sale if your gains are less then the exclusion amounts of $250,000 if filing Single or $500,000 if filing Married Filing Jointly (and both lived in the home for two years).
If you had a gain greater then the exclusion amounts then you would have to report the sale. Also, if you received a Form 1099-S for the sale either with a gain or a loss, the sale has to be reported.
You cannot report the sale of property in 2017 on a 2019 tax return.
If you did not report the sale on the 2017 tax return and now need to report the sale then you Must amend the 2017 tax return that was filed. Or if you need to change what was previously reported for the sale, then you Must amend the 2017 tax return that was filed.
Depending on which TurboTax program you used, online or desktop, the procedure to amend the 2017 tax return is different.
If you used the TurboTax online editions for the 2017 tax return then you have to download the 2017 Amend software to install on your personal computer. And you have to download the 2017 tax data file from the 2017 online edition to transfer to the Amend software. As described in this TurboTax support FAQ - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-turbotax-online-return/01/27371
