National Health Insurance NHI Requirements?

What are the requirements for foreigner for NHI? Visa, ARC, local ID number for getting a bank account, driver’s license, what??? Any of these or something else?

I have insurance from home, but it is quite difficult to file, and many times they don’t agree or understand the charges. Except for extreme circumstances, it would be easier for me to have some easy cheap local health insurance.

Went to the emergency room last night for food poisoning. Saw two doctors, had an IV for hydration, an injection for pain, 3 prescriptions, and rested in bed for six hours.

Cost in Taiwan: NT$2850
Cost back home: NT$N$20,000-25,000 or more…

Is there a guide or website?