Is it okay to fill an espresso machine with milk instead of water?

If I fill the water compartment of my espresso machine with milk instead of water will it clog/ruin the machine?

I’m not talking about the frother, which is used to frothe milk. I’m talking about the water compartment that you put water in, which makes steam, which makes espresso. Anyone who’s ever owned an espresso machine will know what I’m talking about. Any help would be really appreciated. Thanks!
has anyone actually done it?