Finaly received my pin for tax now to enter it one the tax form how do i do thatg

I am assuming you mean the 6 digit IP PIN.

Here is where that goes:

1. Sign in to your account and open your return.
2. Select Federal from the left side menu.
3. Select Other Tax Situations toward the top right.
4. Scroll down/ expand the list and look for Other Return Info.
5. Expand the section and  click on Start or Update to the right of Identity Protection PIN.
6. Answer the first question Yes.
7. Select your name and click Add to the right.
8. Enter the number on the next screen. 
9. At this point, you can complete and file your tax return.