Why is 'Apple Intelligence' not appearing on my MacBook Air after updating to macOS Sequoia 15.4?

Okay, so this may sound weird, but it’s true. This morning, I updated my MacBook Air with a M1 chip to macOS Sequoia 15.4, and I set my language to English (U.S) and live in China. Siri and Device Language are both English. Apple says that Chinese and English of Apple Intelligence is available, but WHY it does not appear??? All it says is “Siri” and NO OPTION NAMED “Apple Intelligence”. JUST WHY?

[Re-Titled by Moderator]