Are you an Advantage member with an annual subscription? Was it registered to you or your late husband? If it was your late husband's account, are you able to log into the Advantage account that was used?
If you can log in, see this FAQ on how to cancel an Advantage subscription:
FAQ: How do I cancel my TurboTax Advantage subscription?
I tried that and it didn't work. Can't I talk to a human and help me get this done?
If the credit card on the account is no longer valid then the account will automatically be closed .
@william-francesc wrote:I tried that and it didn't work. Can't I talk to a human and help me get this done?
I'm not sure what "didn't work" means since you didn't describe the roadblock. But if you wish to talk to someone at TurboTax Support, you can use this contact form to get a phone number during business hours:
https://support.turbotax.intuit.com/contact
For product, indicate in the dropdown list that you are using the CD/download version.
Hours are 5AM-5PM Pacific (8AM-8 PM Eastern) Monday-Friday.