how to subscribe to an observable from another file code example

Example: create an observabloe js

content_copy
      
      
        open_in_new
      
      function foo() {
  console.log('Hello');
  return 42;
}

const x = foo.call(); // same as foo()
console.log(x);
const y = foo.call(); // same as foo()
console.log(y);