"...in 2018..." ? Are you asking about a tax year 2017 return that you filed in 2018----or are you asking about a tax year 2018 return that you filed in 2019?
And you are asking about it in 2022? What does it say in your TurboTax account? Does it show that the e-file was accepted or does it say something else--like "rejected," "printed," or "ready to mail." If it says accepted then you have to ask the IRS. If it says "rejected" or anything else, then it is too late for you to file it and get your refund. If the e-file was rejected then you had until October of 2019 to fix it and re-file it, or you had until April of 2022 to mail it in and still receive your refund.
Make sure you are looking in the right account:
Many people have multiple TT accounts and forget how to access them. Log out of the account you are in now.
Account recovery
https://myturbotax.intuit.com/account-recovery/
https://ttlc.intuit.com/questions/1901535-forgot-your-turbotax-online-user-id-or-password
Or did you use the desktop version of TurboTax? If so, the files are on your own hard drive or any backup device you used like a flash drive.
https://ttlc.intuit.com/questions/1901486-how-many-turbotax-accounts-do-i-have
https://ttlc.intuit.com/questions/1901535
https://ttlc.intuit.com/questions/1901659-find-your-tax-data-file-in-mac
https://ttlc.intuit.com/questions/1900721-find-your-tax-data-file-tax-file-in-windows
To get a copy of your previously filed returns prepared with online TurboTax https://ttlc.intuit.com/questions/1900748-how-do-i-get-a-copy-of-a-return-i-filed-in-turbotax-online
Either you never really filed, or you refund was taken for other past-due obligations.
It is not past the deadline to file 2018 tax return for a refund.
@fanfare It is past the deadline to get a refund for a 2018 tax return unless you had an extension for 2018.
You can also check to see if the IRS has a transcript of a 2018 tax return for you. Or check your IRS online account.
You can get a free transcript from the IRS:
https://www.irs.gov/individuals/get-transcript