How to Object.defineProperty on custom window object in Angular?

For instance I have YOTI object injected into browser:

When I run this in console:

window.YOTI

I get:

{onShare: ƒ, redirect: ƒ}

Then if I access redirect method I get this:

window.YOTI.redirect

ƒ (callbackUrl, token) {
                var currentQuery =  window.location.search.replace('?','')
                var currentFragment = window.location.hash
                var separator = (callbackU…

I want to modify this property in angular onInit() and I tried this from here(https://yoti.zendesk.com/hc/en-us/articles/360008958873-Does-the-Yoti-frontend-client-support-an-Angular-App-):

const ytcontainer = {
};

Object.defineProperty(window, 'YOTI', {
  get: () => ytcontainer.YOTI,

  set: yoti => {
    ytcontainer.YOTI = yoti;

    Object.defineProperty(yoti, 'redirect', {
      get: () => {
        return (callbackUrl, token) => {
          console.log(callbackUrl);
          console.log(token);
        };
      },
    });
  },
});

but after that, when I run window.YOTI I get undefined object.

window.YOTI
undefined

What am I doing wrong here?