IP Pin

Here's how to get to that section: How do I add or remove my 6-digit IP PIN?

I was able to click submit but now I’m concerned my return will be rejected. Is it possible it went through ok or is there anything I can do now?

Don't worry if it gets rejected - you are considered as filed on time.   

If your return is pending, you should be fine. Your submitted e-filed return doesn't need to be accepted on May 17 for it to be considered on-time. As long as you transmitted your return by 11:59 p.m. local time on May 17 you should be fine.

If your return is rejected on May 17 you'll have through May 22 to re-submit your federal return by e-file, or mail your return.