Background-image in CSS not working in Phoenix 1.6

OK, I searched a bit and found this: Image assets in CSS on Phoenix 1.6.0-rc.0

So, in /config/dev.ex I replaced this line:

{Esbuild, :install_and_run, [:default, ~w(--sourcemap=inline --watch)]}

eith this line:
{Esbuild, :install_and_run, [:default, ~w(--sourcemap=inline --watch --loader:.png=file)]}

And, finally, it WORKS!

Now, another problem, how to support .jpg and .gif or all images as well? Because I don’t have only png files I use for background-image in my CSS.

I guess I have to somehow put more image formats in here: --loader:.png=file , right?

Any idea what is the correct format?