If you're asking about filing a return for someone else, you'll need to set up a separate TurboTax account for that person. See the information below regarding starting a second return using TurboTax online.
https://ttlc.intuit.com/replies/3288574
*** I am NOT a tax expert. I am a seasoned TurboTax user, and volunteer to provide assistance to TT users. Nothing I post is to be considered TAX ADVICE; I bear no legal liability for responses.***
