TurboTax accounts cannot be deleted nor can the data from a prior year account be removed.
You can have the account deactivated by contacting TurboTax support.
See this TurboTax support FAQ on how to contact Support - https://ttlc.intuit.com/questions/3401489
Submit your question/problem during business hours and then use the option for Call (a phone number will be provided for Call) to speak directly with a TurboTax agent -
Note: The Call option will not be available when TurboTax Support is closed.