Chat GPT extension is missing in Sequoia 15.2

I purchased an IMac last week in Canada and it came with Mac OS Sequoia 15.1 operating on M4 chip. Like most people, I joined the wait list for Apple Intelligence and was able to make it work by selecting English (US) as the language. I then learnt about Chat GPT extension available in Sequoia 15.2 and updated my OS to 15.2 but there is no ChatGPT extension. The help docs however say “Select ChatGPT” but I don’t see it. It is not very clear if I need to download the extension separately. Please advise if you have had success in a similar situation.