Notebook studies?

My sister needs a new notebook for her studies. I know my way around PCs, but I can't quite find the right one. You want a notebook with a detachable keyboard, touch display, fhd, 12-15 inches, 1tb memory, ideally ssd, and the cpu shouldn't be too bad either. Ram 8gb, 16 is also possible and the integrated graphics unit of the cpu is sufficient as a gpu. Price range 400-900 euro.

no apple please

Unfortunately I don't find anything reasonable in this price range. I would maybe dig a little deeper at this point or use less memory. Otherwise, you could check out the Surface Book series.

With a detachable keyboard?

That's pretty difficult in this price range.

A Surface pro 7 may then be the best choice, although I'm not sure whether you can equip it with 1 TB of storage and, if so, how much it will cost.