See this TurboTax support FAQ if your license code is not working - https://ttlc.intuit.com/community/tax-topics/help/my-code-doesn-t-work/01/871966

For a license code issue please contact TurboTax Support by phone during business hours 5AM-5PM Pacific (8AM-8PM Eastern) Monday-Friday.  

Not a helpful page. But the only attempt at helping that I've found in a wasted hour of seeking help from Intuit.

My installation was fine until I tried to open my return (after IRS says I owe more penalty than Turbotax calculated and put in my tax amount - good job). Can't open the program without submitting to a forced update. Now program requires me to enter my license (again) and then says it's invalid, code 607.

Can't get anything about Code 607 from any of the (so-called) "Help" resources.

Intuit broke my paid-for software and now prevents me from accessing my paid-for returns.

Did you see this one?  

Turbo Tax asks for the License Code each time you start

https://ttlc.intuit.com/community/tax-topics/help/turbotax-2019-requests-license-activation-at-every-launch/00/960924

WHEN WILL GET LICENCE CODE? I ORDER ON LINE ON NOV.1 PLEASE LET KNOW.

See this

https://ttlc.intuit.com/community/license-information/help/as-a-turbotax-advantage-and-pre-order-customer-why-am-i-not-seeing-my-license-code-for-my-2021/00/2371157#M7846