You can use any version they need.  You can NOT use your account.

The Online version is only good for 1 return. But you can use the same email address for 5 accounts. To do another return log out of your account and set up a new account and new user name and pay any fees again. That's why it's better to use the Desktop CD/Download program. The Desktop program can do more than 1 return and efile 5 for free.

How to start another return in the Online version
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-online/00/25596

They might qualify to use the Free Edition or the Free File website. Turbo Tax Free File website is free for federal and state. And has more forms than the Federal Free Edition, like the full 1040 return and Schedules A, B, C , D, E, F, EIC, H, K-1, SE, etc.

To qualify for the Tax Freedom website you just need to meet one of these 3 things
AGI $36,000 or less
Active duty military with AGI of $69,000 or less
OR qualify for EIC (earned income credit.)

In order to use the Turbo Tax Free File, you have to start it at a special website. If you use the Sign In button on the top right I hear it brings over your work.
https://freefile.intuit.com

How do I start another return in TurboTax Online?

Never start another return by going back and overwriting everything in the return you just filed. This will replace your info, which means you won't be able to retrieve your return later.

You might want to switch to the TurboTax CD/Download software to save money

• Unless the additional return/s you want to file in TurboTax Online are simple returns and can be filed using the Free Edition, there is a charge for each additional return filed in TurboTax Online.
• On the other hand, the TurboTax CD/Download software lets you file up to 5 federal returns at no additional cost. More info

If you still want to start another return in TurboTax Online, here’s what to do:

1. Sign out of TurboTax Online.
2. Select the TurboTax Online product you want to use for the second return and proceed.
3. On the Create your account screen, set up a new login for the second return.
   • You can reuse your email address if you want to receive e-file notifications for the second return.
   • Up to 5 accounts can be tied to the same email address.
4. After you've created the new account, you can start working on the second return.

You may wish to use one of the IRS FREE FILE options for their returns if you have state returns that need to be filed ...  https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free