Online is only good for 1 return per account. So if you did his return in your account it overwrote your return and yours is gone for good. Or you used a different account. You will need to setup a new account this year for you.
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
How to view all your accounts
https://ttlc.intuit.com/turbotax-support/en-us/help-article/account-management/many-intuit-accounts-turbotax/L9aVfKS1Z_US_en_US?uid=ll5g6zcx
It's common to end up with multiple accounts. First LOG OUT of whatever TurboTax account you're logged into right now. Then use this TurboTax account recovery website to get a list of user ID's for an email address. Run the tool against any email addresses you may have used
https://myturbotax.intuit.com/account-recovery/
The TurboTax online editions can only be used for one tax return per account and User ID. If you completed your tax return with this online account and then completed your friend's tax return using the same account then their tax return overwrote your tax return. Your tax return is gone.