If you have $1,000,000
Did I get the figures correctly? $1,000,000 (One million dollars) in the last 7 days—does that not sound impossible for one to win the promo code? And even if one wagers that amount, what will the $1,000 bonus be to him or her?
I don't think that's the case. I suppose the $1,000,000 wager amount is just the accumulated amount you need to have at least to be eligible to claim that promo code.
OP, did these codes really come from Stake? If yes, could you provide any links posted by their official social media accounts so we can check them out and verify?