Before filing the 2018 tax return using the online editions you had to pay the TurboTax online account fee for the edition you were using with a credit card. Or if you were receiving a federal tax refund you may have been able to select the option to have the TurboTax account fees deducted from the federal tax refund.
Since you did not file the 2018 tax return see this TurboTax support FAQ for completing a 2018 tax return originally started with the online editions - https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-finish-a-prior-year-return-that-i-...
