If you need to file a Joint federal and separate state returns
Reading the FAQ it looks like you have to use 3 accounts. One to file the Joint return. Then you each need another account to fill out fake federal MFS returns to do your separate state returns. So you will have to PAY for 3 online accounts (3 federal returns and 2 state returns). That's why it's cheaper to use the Desktop installed program. If you don't have a computer to install the desktop program on maybe it would be cheaper and easier to go to a local accountant or tax place.
Online is only good for 1 return per account. But you can use the same email address for 5 accounts. How to start another return in the Online version
Or buy the Desktop CD/Download program here
Are you aware of the VBTA Act of 2018, which states that if a Servicemember is a legal resident of a particular state for tax purposes, the spouse can unilaterally elect to also be a resident of that same state?
See page 3 of this reference:
https://www.jag.navy.mil/legal_services/documents/Info_Paper_2018_SCRA_Amendments.pdf
And the "Military Spouses" section of this reference:
https://www.defense.gov/Explore/News/Article/Article/1740689/