Z5/6/7(ii) uses the rectangular accessory connector on the left side that has been in use on the non-professional bodies for more than a decade. The DX Zfc and Z50 both got dudded due to not having an accessory port connection.
Most days I still use a 10+ year old Hahnel shutter release cable from my old D90 on my Z7 and it works perfectly fine. It’s more or less just a copy of the Nikon MC-DC2 cable so anything compatible with the D90, D5xxx/D7xxx series cameras that also has that rectangular style DC2 cable connection will be compatible with the FX Z cameras.
Examples of the cable you’d be looking for.
https://www.hahnelusa.com/irish-shop/hrn-280-pro-for-nikon/
Pixel stuff is also good. Used their intervalometer style cable on my D810 for a long time.
I also have the Hahnel Captur for Nikon wireless trigger/receiver set using the “N3” cable which works fine too but is more expensive if you don’t need the wireless triggering or intervalometer stuff.
The cables you want to avoid are the Nikon MC-30 style ones with the ROUND connector which won’t work at all with Z bodies.