In a sensible world landlord would purchase the unit in the first place for tenant. It's somewhat common in here that if you want to use your own time and effort to make your (rental) home nicer the landlord pays for the materials. It's commonly used for things like paint or wallpaper, but replacing kitchen kabinets or other bigger renovations are not unheard of either.

But yeah, that's obvious issue which should be resolved before installing anything. I wouldn't buy 1000+€ unit as a gift for the landlord. And you'll likely need a permit or two before drilling trough apartment walls anyways.