Calling A LUA Function From C++?

[DY357LX]

Let's say I have hello.lua file that simply reads:

function hello()
io.write("Hello from LUA!")
end

How do I call this function from a C++?

I've read a few tutorials and sample code but they appear to be outdated and I run into a lot of errors that read:
"PANIC: unprotected error in call to Lua API (attempt to call a nil value)."

Thank you.