Bootstrap code problem (functions.php)

Hi, I’m trying to use bootstrap with Contact Form 7.

I followed this tutorial: Bootstrap Modal + Contact Form 7 but when i insert the code in functions.php worpress say it has an error. The code:

function BH_scripts() {

     wp_enqueue_script( 'bootstrap-modal', get_template_directory_uri() . '/scripts/modal.min.js', array(), null, true );

    wp_register_style( 'modal-css', get_template_directory_uri().'/css/modal.css', array(), null, 'all' );
    wp_enqueue_style( 'modal-css' );
}

add_action( 'wp_enqueue_scripts', 'BH_scripts' );

I’m not sure if i’m inserting the code on the right place, or if i have to modify something else.

The idea is to generate a lightbox with the contact form using Bootstrap.

Any help is appreciated!
Thanks in advance.

https://www.ads-software.com/plugins/bootstrap-modals/