Creating object for Map interface in TypeScript

Here by using "new" keyword I am creating object for Map interface (in Java we cannot create objects for interface, generally). I do not understand, without implementing Map interface which is TypeScript based, how the code works?

let map1= new Map()
map1.set(12,"User1");
map1.forEach((k,v) => console.log(k,v))

In Java I am implementing the interface Map using HashMap class, I am able to create object of HashMap class. In Java, I am not allowed to create Map object using "new" keyword:

public class User{
    public void createMap(){
        Map<Integer,String> map1= new HashMap();
        map1.put(12,"NameOne");
    }
}

JS Map is a class, not just an interface

If it would be interface, you'd get this error