Hi,
So we have some bad news on this one, The Ask AI in the code node was incorrectly announced and it is not available in the self hosted version of n8n at the moment, this may change in the future.
We also made the choice recently to remove the Ask AI beta option for the HTTP Request node, The best approach for this now would be to use a mix of the AI nodes and the HTTP Tool which will give you more control.
Sorry for the bad news, I will get the docs updated and the main post now.