Where I have to enter the PIN (error 181) in my TurboTax Delux software, please?

If you received an efile rejection error code IND-181 that's due to a missing IP PIN, which is a 6-digit Identity Protection PIN.    If you have your new 2025 IP PIN for use on your 2024 return, here's how to enter it:

I don't know for sure if you are using Online TurboTax or the desktop version.  Since you used the term "software", I'll go with desktop TurboTax.   It's similar in Online TurboTax, but if you need specific help with Online TurboTax, report back.

Federal Taxes tab.

Subtab Other Tax Situations.

Scroll way down to Other Return Info.

For subtopic Identity Protection Pin click Start or Update.