Redirect blog

Hi,

I’m trying to make a very simple plugin that will redirect a blog post to another page if a query string is present.

Here is my code:

function triplify_init()
{
	global $blog_id;
	if(isset($_REQUEST['triplify']))
	{
		$http = 'https://';
		$https = $_SERVER['HTTPS'];
		if(!empty($https)){
			$http = 'https://';
		}
		header('Location: '.$http.$_SERVER['SERVER_NAME'].'/triplify/'.$blog_id.'/');
		exit();
	}
}
add_action('init', triplify_init());

The plugin is activated however if I go to https://example.com/?triplify nothing happens (it just loads the page like normal) however if I go to https://example.com/wp-admin/?triplify the plugin does run.

My understanding is that the init action should run regardless of what page you’re looking at.

Can anyone point me in the direction please?

Thanks