If you did mean that you withdrew the funds in 2018 and returned the funds in 2019 in 60 days or less, that withdrawal should have been reported on your 2018 tax return using the 2018 Form 1099-R that you received.
If you have already filed the 2018 tax return and did not enter the 1099-R on that return, you will have to amend the 2018 tax return to report the withdrawal.
See this TurboTax support FAQ for amending a 2018 tax return originally completed and filed using TurboTax - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-a-return-in-turbotax/01/27579
