Where are some places you can sit Te Kura externals (if you are just enrolled with Te Kura)

Say you're just enrolled with Te Kura, not dual enrolled. Do you go to a local school to sit your externals? Do all schools let you come and sit them? Do you have to pay? What if you have special conditions of assessment eg separate accommodation, can that happen?

Also if you are in health school for some reason, where would you sit your Te Kura exams then?

Thanks in advance, would just appreciate any insight or useful info.