What is the Ember Octane replacement for `didInsertElement`?

I’m trying to fire a callback passed down from a parent component. Our old pattern for handling this was to call the function in didInsertElement. In Octane, I see that we can use the did-insert modifier but that seems weird for this use case since we’re not updating the DOM element that we’d use to call did-insert. I've also seen onRender being used in a few cases but I don’t see documentation on that and it’s not firing for me. Any suggestions?

For this specific use case, we have a parent component that can have one of many child components. And for each child component we have specific text that gets displayed in the parent component and we want the child component to be the owner of that text.