Remove Google Chrome from Dock when running google packaged apps

So.. I use Postman - Rest client (Packaged App) which come in google chrome store and can be launched as an app but with google chrome engine.

If I launch this packaged app from dock, google chrome icon will also appear in dock. And if I click on this google chrome icon, google chrome will launch.

How to remove this icon but remain only Packaged App icon (in my case Postman icon).

Thanks!