Also having the same issue, "here's your promo code , went to Amazon and they say the code has expired, tried the day I received 10-4-22, the next day 10-5-22, and now today, is this called " False Advertising" on tmobiles part.  If anyone figures this out, please let us know!  Thank you

I just checked my email. There’s a new code and it worked! Delivery scheduled for tomorrow. 

New code last night and it worked!! 

I also had this problem. I went through the Home internet sales support number and got a very helpful person who made some calls and told me they knew about the expired codes and that I would get a new one shortly. That came yesterday and worked immediately.

Got new code with message"
Oops! We sent you the wrong code - here is your new one. Make sure to redeem by 11/30.

New code worked........ 

No new promo code here !

I did not receive a new code, called today, I had to be persistent but told the rep I wanted a new code before getting off the call. I was on hold for awhile but she did follow through, sent the email while I was on the call and had me try the code while she was on the phone, and it worked! Hopefully I'll receive it in a few days. If you don't receive a new email and new code, call and let them know you want a new code while you are on the phone with them. Good luck everyone!

Got my new code tonight, without calling T-Mobile. (I don’t have the patience for that sort of thing any longer.)  It worked at Amazon and I should be getting the device tomorrow.

Update: T-mobile sent me another email with a new promo code that worked. I received my echo show 8 last week and couldn’t be happier customer. I never want to go back to Verizon or AT&T. Thank you T-mobile!