After you file
When you sign onto your online account and land on the Tax Home web page, scroll down and click on Add a state. 
This will take you back to the 2018 online tax return where you can make any changes necessary.
When you sign onto your online account and land on the Tax Home web page, scroll down and click on Add a state.
This will take you back to the 2018 online tax return where you can make any changes necessary.