@dogeared I know it's been a few days, but just in case you haven't got your second code, you can contact Stadia support and they'll be able to look up the code for you
Go to the link below:
https://support.google.com/stadia#topic=9634925
On top right, click on 'Contact Us' > then request chat/callback to speak to a representative. Try it from a computer browser if the option is not shown on mobile