SOS ! Best text to voice add on app in Adobe Express?

Seeking recommendation of which text to voice add on app in Adobe Express is best for a lot of content? I have to record (today) 3 hours of Slide Decks. Its a lot of speaking at one time. None of the free versions of the add on apps will handle a large body of copy. Before I buy a susbscription to any of them, I appreciate insights as to which one has the best quality for the price to deliver educational material. Thanks!!