Configurator Authentication with panel_iframe

I’ve just installed the HASS configurator as a docker container, and, while it works well when I go to https://mydomain.duckdns.org:3218, after setting it up as a panel in hass (with the url being https://username:[email protected]:3218), it simply displays a blank page after clicking on the panel. I have also tried clearing the cache/force refreshing but nothing changed.

Screenshot of homeassistant

My configuration:

HASS Configurator:

{
    "LISTENIP": "0.0.0.0",
    "LISTENPORT": 3218,
    "BASEPATH": "/hass-config/",
    "SSL_CERTIFICATE": "/ssl/fullchain.pem",
    "SSL_KEY": "/ssl/privkey.pem",
    "HASS_API": "https://127.0.0.1:8123/api/",
    "HASS_API_PASSWORD": "<redacted>",
    "CREDENTIALS": "homeassistant:<redacted>",
    "ALLOWED_NETWORKS": [],
    "BANNED_IPS": [],
    "BANLIMIT": 0,
    "IGNORE_PATTERN": [],
    "DIRSFIRST": true,
    "SESAME": null,
    "VERIFY_HOSTNAME": null
}

HASS:

panel_iframe:
  configurator:
    title: "File Editor"
    icon: "mdi:folder-edit"
    url: "https://homeassistant:<redacted>@<redacted>.duckdns.org:3218"