Huel+ Code Not working

I just redeemed some points for a Huel+ discount code that I thought I could use on any purchase or apply to my subscription, but it doesn’t seem to be working. The code says it’s valid until the end of December 2026, but right after I obtained the code, I went to apply it to my subscription order and click on I NEED IT NOW, but when I add the Huel+ code that I literally just received, I get an error and it says the code is expired or invalid. Is there any way to fix this?