Yes. The IP PIN has nothing to do with paying your tax or paying the TurboTax fees. If you got an IP PIN from the IRS, you have to enter it on your tax return. If you don't, you will not be able to e-file, and your mailed tax return will take longer to process.
An IP PIN (Identity Protection PIN) is a 6-digit PIN provided by the IRS to certain victims of identity theft, but it's also possible for folks to electively opt-in to the program as well. Do you have an IP PIN because the IRS assigned you one or you opted in?
If you are required to use an IP PIN to file your return, and if you lost it or never retrieved it, here's where you can get your IP PIN online:
Once you have the 6-digit IP PIN (if you are required to use one), we can tell you how/where to enter it in TurboTax, if you need help.