Most likely, the software is asking if you filed last year so you can retrieve your AGI. This will likely be during the filing process (under the File tab).
Your AGI is required by the IRS if you plan to efile. If you do not know your AGI or do not have a copy of your prior year's return, you can choose to file by mail. This will allow you to bypass questions about your AGI.
If you do have access to your prior year's returns, it's a simple matter to find your AGI.
https://ttlc.intuit.com/replies/3301618
