How to use local files for Dashboard 2.0 App Icon

I have used httpStatic in settings. js to implement fixed IP address icon access.
But the problem is that my node red host has two network cards, corresponding to different IP addresses. When accessing the dashboard through different network cards, the URL of the icon file is different.
So, I want to know if it's possible to use a method that directly calls local files to set the App icon

I am replying as no-one else has. I think it should be possible to use a relative URL rather than absolute, so it will use the same base as the dashboard, but I don't know how to do that. Hopefully someone else does.