Technically, you can't, but there's no way to enforce copyright infringement on private work.
You can paint a Studio Ghibli-style painting -- the style isn't protected.
These rules assume that copying the style is labor intensive, and righteously rewards the worker.
When an LLM can reproduce thousands and thousands of Ghibli-style paintings effortlessly, not protecting the style seems less fair, because the work of establishing the Ghibli-style was harder than copying it large-scale.
I'm in the "don't fight a roaring ocean, go with the flow" boat:
If your entire livelihood depends on having the right to distribute something anyone can copy, get a stronger business.