To access your prior year return, you would need to upgrade your account to Plus. To do so, make sure that you are in your account. Select Take me to my return (if you haven’t already), then Upgrade in the left-hand menu and choose Plus. Select File in the left-hand menu and continue until you get to Review your order. Then select Start and follow the on-screen instructions.

https://ttlc.intuit.com/replies/5574744

You can also get a copy of your return by doing the following;

• Order a free tax return transcript online or by mail from the IRS that has a lot (but not all) of the information from the return. Some people may not be able to do this.
• Pay the IRS $50 for an exact copy of your return.

Please follow the instructions listed in the following TurboTax FAQ to contact Customer Support if you need further assistance. https://ttlc.intuit.com/replies/3300041