Yes, you would need to Amend your tax return to add the Form. However, you would need to first wait and see if your tax return is accepted or rejected. If rejected, you can go back and add the form.
If accepted, you would need to wait until you have received your tax refund and then you can Amend your tax return and add the form. Here is an FAQ on Amending (2017 Amending instructions will be available soon)
https://ttlc.intuit.com/replies/3288565
