Which hook to use for restricted content

I’m using Restrict Content with a Genesis theme.

I have a function that adds some content to a page. Here is a minimal working example:

function myFunction() {
	echo '<p>Some Extra Content</p>';
}
add_action('genesis_after_post_title', 'myFunction');

My extra content will appear fine, but when it is on a page that is restricted (i.e. to subscribers only) the extra content is still visible. I want it to be hidden like the rest of the page content.

I have tried many different Genesis hooks, but none of them allow me to restrict this extra content.

I also tried a WordPress hook, the_content, but this also didn’t get restricted. Am I going about this the wrong way? Or is it impossible?

https://wordpress.org/plugins/restrict-content/