Joe Biden ‘discussing’ possible Israeli strikes on Iran oil facilities; IDF says it has killed a Hezbollah commander – Middle East crisis live | Lebanon | The Guardian
Oil facilities can be legitimate targets, if they're producing fuels, other petroleum products, or generating electricity, for military purposes. I don't know which facilities are being discussed here, or whether those facilities are primarily military or civilian.
For some people, "war crimes" isn't a legal theory, but a moral outrage. In this case, they've painted themselves into a corner because Joe Biden is already fully responsible for genocide, so adjudicating a few war crimes seems petty and irrelevant.
Never mind that a conflict in the same time-zone as Israel, energy infrastructure is a primary target for both sides.