If you used TurboTax Free Edition for those years, you will need to pay for, at a minimum, the PLUS feature in order to unlock those prior years' returns. Access to prior years is not a feature of the Free Edition of TurboTax. See the TurboTax FAQ below to unlock prior years' returns.
"How do I access my prior year return?"
https://ttlc.intuit.com/replies/5574744