Default image for picture-entity

I Have an ESP32-CAM using ESP home.
sometimes this cam is unavailable, because of wifi issues or poweroutage.

When someone tries do access the this camera at this time HA Immediately shows a notification
“Login attempt failed”
because url
returns a 401.
Is there a way to set a default image or some other way to prevent those annoying 401 requests to stop?

Is there some state you can see that it’s unavailable on?

Yes, the state is Unavailable
but this doesn’t seem to work:

  Unavailable: /static/icons/favicon-apple-180x180.png

Is it Unavailable or unavailable? Look in the developer tools

neither work,
I treid both,
the manual uses quotes, but the lovelace editor removes them for me.