TurboTax does not support tax year 2018.
A 2018 tax return can only be printed and mailed, it cannot be e-filed.
If the 2018 tax return is filed with a tax refund the refund will not be paid since it is beyond the 3 year limit for filing a return after the due date.
If taxes are owed on the 2018 return then it needs to be filed as soon as possible since penalties and interest will continue to accrue until the taxes owed are paid.
Seek out a local tax professional to assist you with completing and filing the 2018 return.
Or go to this IRS website for prior year federal tax forms, schedules and instructions - https://www.irs.gov/prior-year-forms-and-instructions