How to call the method of C # for the object variable defined by JavaScript

[WangDeBug]

js code:
var objstu=obj.create(param); objstu.study( );

Jint error：
Property 'study' of object is not a function

I'm sure jint can be implemented, but I don't know how to write it

[lahma]

objstudy.study = function() {};

[WangDeBug]

I hope function 'study' is the method of c# and implements the c# method of JS operation

[WangDeBug]

_engine.SetValue("obj"，new obj())

[lahma]

Please see all the interop tests in this repository, they describe very many ways to do things.