If you are asking how to remove the "LIVE" option from your return, see the instructions in the TurboTax FAQ below.
https://ttlc.intuit.com/replies/6420172
If you're asking about how to cancel a return you've started in TurboTax Online, you can simply abandon the return. Payment is not due until you either e-file or print your return.
*** I am NOT a tax expert. I am a seasoned TurboTax user, and volunteer to provide assistance to TT users. Nothing I post is to be considered TAX ADVICE; I bear no legal liability for responses.***