IIRC, it was added in one of the charging standards, I want to say it was CCS. In theory every car that supports that charging standard should be capable of it, but in practice that will likely be a different matter. As few people need it, few people are likely testing that it works.

I've heard the hard part right now is more regulatory in nature. Especially in the US where energy regulations vary not just from state to state, but also sometimes regionally within states based on power utility provider for a region.