If you did not enter the expenses for the move on your 2017 tax return you would need to amend the 2017 tax return.
See this TurboTax support FAQ for amending a 2017 tax return originally completed and filed using TurboTax - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-a-return-in-turbotax/01/27372
IRS Publication 521, Moving Expenses (2017) - https://www.irs.gov/pub/irs-prior/p521--2017.pdf
