After you file

Per IRS website: https://www.irs.gov/e-file-providers/self-select-pin-method-for-forms-1040-and-4868-modernized-e-fil..., I need to leave my PIN blank if I am a first time filer.  How can I do that in TurboTax?  TurboTax won't allow me to continue if the PIN is blank.  Thanks!