Side Button Access entitlement not appearing in Xcode capabilities list

Hi everyone,

I'm trying to add the Side Button Access entitlement to my voice-based conversational app following the documentation, but I'm unable to find it in Xcode.

Steps I followed:

1. Selected my app target in Xcode project navigator
2. Went to the Signing & Capabilities tab
3. Clicked the + Capability button
4. Searched for "Side Button Access"

Problem: The "Side Button Access" option does not appear in the capabilities list at all.

Environment:

• I'm developing and testing in Japan (where this feature should be available)
• Xcode version: Xcode 26.2 beta 3
• iOS deployment target: iOS 26.2

Questions:

• Is there any pre-registration or special approval process required from Apple before this entitlement becomes available?
• Are there any additional requirements or prerequisites I need to meet?
• Is this feature already available, or is it still in a limited beta phase?

Any guidance would be greatly appreciated. Thank you!