If you aleady submitted payment, deducted the TurboTax fee from your refund, or registered your product, you cannot erase your return and start from scratch in TurboTax Online. If you have done any of these things, you'll need to manually edit your return.
https://ttlc.intuit.com/turbotax-support/en-us/help-article/change-service-level/clear-start-turbota...
