You can get this “Nikon F Mount Lens to Nikon Z5 Z50 Z5 Z6 Z7 Z6II Z7II Mirrorless Camera Adapter“ on eBay for only $13 (the same adapter is $15 on Amazon):
The adapter does not support autofocus and is mainly designed for non-AI, Ai, and AIS lenses. Here are the details from the product listing: