Please make sure you are logged into the correct TurboTax account, that is the most common reason for not locating a filed tax return.
Please see this TurboTax FAQ for more information: https://ttlc.intuit.com/community/accessing/help/why-can-t-i-find-my-return-in-tax-home-or-my-docs/00/25553
Once you have logged into the correct TurboTax account see this TurboTax FAQ for more information on how to access a prior year's tax return.
You can also obtain a free federal tax return transcripts from the IRS: https://www.irs.gov/individuals/get-transcript