Thanks OP. I ordered an item yesterday after the link in the OP said I was eligible. Couldn’t change the item in my cart to get it delivered to a locker but selecting the locker delivery when adding another one to my cart worked! Initially promised delivery on Sunday which was quickly updated to delivery today. It’s “out for delivery” now.
Funny thing is that it’s still showing that I’m eligible for this promotion! Maybe I can do it again?
Update: It looks like one per customer per account. Also, I have done this before when it was offered a while back.