How is a copy of your W-2 for 2018 going to help you get your refund? Did you file a tax return for 2018, or are you saying that you want to file it now?
If you filed a tax return for 2018 and did not receive the refund, you have to contact the IRS (call 800-829-1040). TurboTax has no information about your refund, and cannot help you get it.
If you did not file a tax return for 2018, it's too late to get a refund now. You had to file your 2018 tax return by April 15, 2022 in order to get a refund.
