The vendor says:
Please note it may take up to 24 to 48 hours to receive this email with the code.
So in other words, it may take 48 hours. The 24 is really there as a decoy, right? If it takes “up to” a range, the early part of the range has no meaningful contribution except to make you think it might be sooner. Which is also what the “up to” part is doing.