Why do you think you need another one? Where? Are you filing a Joint return or separate returns? Joint is almost always better. Online is only good for one return per account. But you can use the same email address for 5 accounts.
How to start a new online return
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-onli...
