Hello,
the key for the "Dawn of the Dukes" expansion for Age of Empires II is a separate one from Age of Empires IV, meaning that I will receive two keys? Or will I receive one key that will activate both Age of Empires IV and the said expansion?

I am asking because I do not own the original Age of Empires II yet (planning to get it during winter sales), so I'd not want to lose access to this expansion because of me activating it along with AoE IV via one key.

Thanks.