I called the Sprint store in San Leandro, CA to see if they had the promo codes first. They did...
I went into the store and there were a lot of challenges on their end getting it to work. event".
(Make sure they pick the correct event - not the expired lure-a-thon events - They wasted 30 minutes of my time before I showed them in a few seconds this mistake
They check me in, I got the 200 points for Trainer Rewards immediately.
They told me an email with the Promo code would come.
It did not...
Went to Trainer Rewards to send a trouble ticket.
They were closed until Tuesday for Memorial Day holiday.
I sent a trouble ticket.
After getting a response and getting to re-send the email - I got the promo code.
How that works
It's a one time code - specific to your account
1 Lucky Egg
5 Great Balls
It happens like spinning a pokestop - sorry about the screenshot missing all the four items ( you can see the spaces the 1st 2 were before the bubbles popped.
I am a Sprint customer (not sure if this matters) with an Android phone (I know this does matter)