Thanks! All three codes entered successfully. Guess I now need to charge at one of my two local evGo stations. I don't normally use them because they are expensive (including a session fee), but free - I'll take that!
I deleted my EVGo account and app and changed my credit card because I got a mystery charge 1000 miles away and have only used EVGo twice in my 5 years of EV ownership. Apparently they do not have good internal security.
Thanks for the tip, I just created an account, guess I might need to wait a couple days to input these promo-codes, at the moment their system is returning an error.