Which model is your MacBook Air? You'll need a Mac with M1 or later.
Apple Intelligence will be available on these devices: How to get the next generation of Apple Intelligence - Apple Support
"Apple Intelligence in iOS 27, iPadOS 27, macOS 27, watchOS 27, and visionOS 27 are available on iPhone 16 models or later, iPhone 15 Pro, iPhone 15 Pro Max, iPhone Air, iPad mini (A17 Pro), MacBook Neo (A18 Pro), iPad models with M1 or later, Mac with M1 or later, Apple Vision Pro, Apple Watch Series 9 or later, Apple Watch Ultra 2 or later, and Apple Watch SE 3 when paired with an Apple Intelligence-enabled iPhone; some features require iPhone nearby."
For the supported regions see: How to get Siri AI - Apple Support
Apple is very vague about the supported regions:
"Siri AI is available in beta for iOS 27, iPadOS 27, macOS 27 Golden Gate, visionOS 27, and watchOS 27 when your device language and Siri language are set to the same supported language and your Apple Account is in an eligible region.....
Siri AI is currently available in English. Availability varies by region and platform. After you turn on Siri AI, it will continue to work when you travel to other regions.
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