Getting is_single to work in functions.php

Hi, I’ve encountered what seems to be a syntax error on my behalf. I would like to use this code in my functions.php:

if ( is_single() ) {
add_action('init','copy_script');

function copy_script() {
    wp_enqueue_script( 'copy-script-js', get_template_directory_uri() . '/js/copy.js', false, null );
}
}

However, the javascript doesn’t get loaded up anywhere. If I use it like this, it gets loaded properly, but for all pages:

add_action('init','copy_script');

function copy_script() {
    wp_enqueue_script( 'copy-script-js', get_template_directory_uri() . '/js/copy.js', false, null );
}

I’m thinking this is a syntax issue. I want the script to be loaded up only on single pages. I would be glad if anyone could help me with this.

ggg377