When you e-file a tax return there is no physical signature on the Form 1040. You "signed" electronically by entering your AGI.
The other forms you mention are only used by paid professional tax preparers. You used "do-it-yourself" tax software. You can keep the bank happy by using a pen to sign your Form 1040 on the line that says "Sign here", but you will not have any 8878/79 to give them. You might need to talk to someone at the bank who has a better understanding of the way that millions of taxpayers use software to prepare their own tax returns.