This is only available in Bard. The APIs for Vertex still say it's in GA, but then you have to call Google to get access, even if you are a trusted developer. A

This is only available in Bard. The APIs for Vertex still say it's in GA, but then you have to call Google to get access, even if you are a trusted developer. And, there are no docs, just a vague POST request example that probably won't work if you don't have access. Even the Vision studio has it locked down for use. This was the case several months ago, and still is. Google's cloud service is great, but dealing with any humans there about getting access to non-access things is a painful process.