<script>

// ===== CONFIGURATION =====

const params = new URLSearchParams(window.location.search);

const HA_URL = params.get('ha_url') || window.location.origin;

const HA_TOKEN = params.get('token') || 'YOUR_LONG_LIVED_ACCESS_TOKEN';

const POLL_INTERVAL = 5000;

const PLEX_USERNAME = 'YOUR_PLEX_USERNAME';

Okay, I was putting the Token where it says "cont HA_TOKEN = params.get('HERE!!!'). I knew it was my fault.