It depends. Click the link for more details about troubleshooting the installation and consider re-downloading the state

• Download TurboTax State (Windows)
• Download TurboTax State (Mac)

And also an article in the community for a first-hand experience downloading the Costco TurboTax program.

If the Costco TurboTax copy was an e-delivery, please check your email for the code or try this Troubleshooting article for help finding the License Code.

For those with the Disc purchased from Costco, it should be included in the packaging or on the disc:

If you obtained the TurboTax CD from an authorized retailer, your license code is printed on the front of the insert in your box. 

If you obtained the TurboTax CD directly from TurboTax.com, your license code is printed on the packing slip.

If you obtained the TurboTax CD through TurboTax Advantage, your license code is printed on the envelope.

@ThePooh

I need my product code. TurboTax Deluxe 2019.

I have misplaced my discs and box.

@jeprevet 

Did you purchase the CD from TurboTax or a retail store?  You can ask customer support on Monday--but if you purchased from a retail store, not sure if they can help with that.  

To call TurboTax customer support

https://ttlc.intuit.com/questions/1899263-what-is-the-turbotax-phone-number

They are available from 5 a.m. to 5 p.m. Pacific time Monday-Friday.