Isolate Vue2 app inside Vue3 page

<body>
<script src="https://unpkg.com/vue"></script>
......
.... Vue3 app ....
......
	<div id="my_Vue2_app"></div>
......
......
</body>

Im trying initialise my vue2 app inside page which inject Vue3 by <script src="https://unpkg.com/vue"></script>
And my app does not work throwing error
image
Is it actually possible to achieve to have working two Vue app with different versions of Vue (Vue2 and Vue3) at same page ?

Welcome @DaimonX
If you have a vue2 application you can include vue 3 composition api for better experience and reactivity.

  yarn add @vue/composition-api
  npm install @vue/composition-api

but vue3 has all the necessary features from vue 2 and plus composition api. You can also use option api in vue 3.
refer here for more.

and

Thank you for reply.
But my Vue2 app can be injected inside many CMS like wordpress, etc… And some of them injects different versions of vuejs in header as Vue2 or Vue3. I need some how completley isolate my css and js inside. Ive tried mount my app in shadowroot it helps isolate css but not js