Can you use Polaris in a Shopify App Extension?

I am building a Shopify post-purchase extension. I would like to use Polaris but it does not seem Supported.

For example the following code yields this error:

return (
    <AppProvider>
        <Page title='test'></Page>
    </AppProvider>
  );
ExtensionSandboxPostPurchase.latest.en.60c73383f0f7ed657108.worker.js:1 Uncaught (in promise) Error: Unsupported component: h1

Is it possible to use Polaris in an app extension?