ERROR (MainThread) [homeassistant.components.panel_custom] Unable to register panel xxx: Either js_url, module_url or html_url is required.

ERROR (MainThread) [homeassistant.config] Invalid config for [panel_custom]: [html_url] is an invalid option for [panel_custom]. Check: panel_custom->panel_custom->0->html_url. (See /config/configuration.yaml, line 22). Please check the docs at https://www.home-assistant.io/integrations/panel_custom

ERROR (MainThread) [homeassistant.setup] Setup failed for panel_custom: Invalid config.