Is OpenAI Image Generation free?

I'm curious, can you clarify for me if OpenAI's Image Generation service is offered free of charge? I've heard some rumors that it's a paid feature, but I'm hoping to get a definitive answer. It would be great if you could provide some insight into whether or not there's a cost associated with using this advanced image creation technology. Additionally, if there are any limitations or restrictions to be aware of when utilizing the service, I'd appreciate it if you could also touch on those points.