Using Plugin Outlet Connectors from a Theme or Plugin

You can see an example here:

StatBanner is a native class defined in components directory:

In your case, that would be api.renderInOutlet("above-main-container", YourClass)

I don’t think you can do it in the HEAD file. You should split your code into multiple files.

I encourage you to use Discourse Theme CLI as it will be much easier to develop a Theme component!

Is your Theme Component public?