After you file

@RicoWarner 

presumably you hunted down the six-digit PIN by finding the letter the IRS sent you. You can't e-File without it.

The IP PIN and the self-select PIN are two different things.

don't enter a five-digit PIN for authentication if you don't have one.

If your 2020 return was delayed, entering AGI = zero may get your e-File to go through.