I just e-filed my returns and they were accepted. I just noted that I did not enter one of my HSA forms, which will change my federal tax owed slightly. How do I amend?

I just e-filed my returns, and they were accepted. However, I just realized I neglected to add information from my 1099-SA, which would change my Federal Tax owed slightly. How do I amend this return? I already entered the updated info In my return. 
My TurboTax is downloaded via code from Amazon