I want to do a file transfer but when I select that option ( already logged in) it asks if: Would you like us to help you sign into your account?

It sounds like you haven't signed into your TurboTax account using the same username and password that you used when you prepared your return last year. TurboTax is suggesting you sign into another account because it doesn't see any returns from the prior year for transfer in the account you're signed into.