Doesn't work for me either, I'm in the UK and I even got a notificatoin with the update today and when I click on the link it tells me I can create images now, but when I enter a new prompt it tells me:

> I can't create images yet so I'm not able to help you with that.

That is hugely disappointing. Don't tell me a feature if available now if you haven't managed to roll it out yet. Doesn't create a lot of trust in Google's engineering TBH.