Landscape material: apply dynamic textures based on slope [help!]

I hope you’re all well.

I am very new to Unreal, so please feel free to point out if i’m being an idiot… I have looked at every single possible post in this forum and all throughout the wonderful internet, but I cannot find anything to help me.

I am trying to create a landscape material that will do the following:
Apply variable textures based on slope (ie rock for cliffs and grass for plains)

I’ve tried importing a height-map using the trial version of World Machine, but I can only get this to work in v4.12. In 4.14 the material just shows up as solid black. I think there must be a better way anyway, because if I change the landscape the texture won’t change dynamically - which I’d like it to do.

I’ve looked at the following support docs but they haven’t really helped (I think the Stylized one is what I want, but I dont really understand it):

Any advice?

Thank you!