No, we do not ask for your signature to use your return for anything other purpose than preparing and filing your federal and state (if applicable) tax returns.
If you choose to pay your TurboTax fees from your refund, The Bank Refund Process Agreement also requires a separate signature; see more about Bank Refund Processing Agreement: https://ttlc.intuit.com/replies/3301372
To remove refund processing fees and pay
with your debit or credit card (before e-filing your federal return) see FAQ below:
https://ttlc.intuit.com/questions/1900517-how-do-i-remove-the-refund-processing-service-and-change-my-payment-method-to-credit-or-debit