The Zappar package is currently supported for Unity's iOS, Android and WebGL build platforms. You can switch between, and build, for each of these platforms without making any code or scene changes.
Please read the articles in this section to learn more about the considerations you should take when building for the different platforms:
If you're building for iOS or Android, or you'd like to self-host a WebGL build on your own domain, you must register your app/site with ZapWorks. For more information see the Licensing article.