How do i go back and add my irs pin? I didn't get the section where I add it.

If you have a 6 digit PIN issued to you by the IRS you need to enter it in order to e-file.  Go to Federal>Other Tax Situations>Other Return Info>Identity Protection PIN and enter the six-digit PIN.

Thanks so much for your response. Unfortunately I need to know if there's a way to enter the irs pin after i hit submit? I didn't realize I hadn't put it in until I was finished. I did not see a section that asked me to put in my irs pin. 

No, you cannot add it after e-filing.  But the e-file will likely be rejected in the next few days, so you can add it when it is rejected and then re-file.

Thankfully they rejected my return about 20 minutes after I filed with very clear instructions and a link to enter my irs pin. I was able to refile immediately, Whew!