Steaming breast milk

Can you steam breast milk (in the bag ) over a bottle warmer ? Like laying it across it . Just told someone to not do that and to only heat it in a bowl of warm water or put it in the bottle and warm it or maybe run it under warm water. They responded with that’s what works for me and who said it has to be done that way. 😑

Am I wrong? Or can it be done that way.

I would think the steam would melt the bag or it would be heated unevenly.