If you are using the TurboTax online web-based edition, there is no license code to enter. You purchased software to be installed on a personal computer, not to go online to do your tax return.
See this TurboTax support FAQ for entering the license code when installing the TurboTax desktop software - https://ttlc.intuit.com/turbotax-support/en-us/help-article/license-information/install-turbotax-cd-download-software-license-code/L1wFOSXur_US_en_US
Looks like the prior link didn't post right. You need to download and install the Desktop program. If you filled out your info in the Online web version you can move it to the Desktop program without paying for Online.
How to get started with the Desktop program, install and activate it
https://ttlc.intuit.com/turbotax-support/en-us/help-article/product-delivery/download-software-turbotax-com/L7u9oLEkq_US_en_US?uid=luqgvzrd