Library doesn't work when using iframe as normal app

[jcubic]

So I've created this app:

sysend.on('input', text => {
    console.log({text});
    input.value = text;
});
input.addEventListener('input', () => {
    console.log(input.value);
    sysend.broadcast('input', input.value);
});

but it doesn't synchronize from page to iframes. It only works for iframes to the main page.
Probably because iframe works in proxy mode, not as an app.

It should work somehow, so you can demo the library.

[jcubic]

Because of this Codepen demos doesn't work:

https://codepen.io/jcubic/pen/BaJQrYV?editors=1111

[jcubic]

The solution may be a function that should and will be called on a proxy file.
Maybe proxy without argument.

sysend.proxy()

this will indicate proxy file.

[jcubic]

The issue is fixed. Will create another demo. This will probably also allow using the library on Codepen and CodeSandbox (for now in single way channel, allow single iframe proxy is tracked in #37)