In need of difficulty levels

upon a campaign start it would be very nice to be able to chose if the combats in the whole campaign would be as they are now, easy, or hard, or very hard. I prompt franz everytime to give me a hard battle with higher CR, but it gets boring to remind him every 20 minutes as franz is a goldfish. I don’ have a human group to play with, i’m not the only one, and I think a lot of people who play DnD exclusively on friends and fables are, like me, potential long term paying subscribers, providing they get real challenge.