Wordpress open accordion code snippet. Request failed with status code 418 on dreamhost

Question

I am very new to javascript and php.

I am trying to write script in the Code Snippets plugin for a wordpress site to make anchor links to accordions open the accordion.

For example, the URL https://challengingbehavior.org/pyramid-model/overview/resources/#generalResources when clicked, should open the page, then scroll down to and open the accordion 'General Resources' with ID #generalResources.

Here is the code I created

function add_this_script_footer(){ ?>

<script>

$(document).ready(function(){
var hash = window.location.hash;
if(hash){
var element = $(hash);
if(element.length){
element.trigger('click');
}
}
});

</script>

<?php }

add_action('wp_footer', 'add_this_script_footer'); ?>

When I try to activate the snippet, it gives me the error "Could not create snippet. Request failed with status code 418."

screenshot of code with error

I found this online... https://wordpress.org/support/topic/could-not-create-snippet-request-failed-with-status-code-418/ But not knowing enough about code, I don't know if this is my problem or something else.

If it matters...Dreamhost, Wordpress 6.4.2, PHP 8.3.

Any help would be appreciated.

Update: Here is the code I put in the functions.php file instead. I am getting syntax errors and it causes an critical error on the site.

//anchor link open accordion

function anchor_open_accordion() { 

    $(document).ready(function() {
        var hash = window.location.hash;
        if (hash){
            var element = $(hash);
            if (element.length){
                element.trigger('click');
            }
        }
    });
}

add_action('wp_footer', 'anchor_open_accordion');
    

Screenshot with error lines

Can someone tell me what change I need to make to my code to get it to work?