How do I install Accessory Developer Profile for CarPlay/Enhanced Siri

Where do I find and how do I install Accessory Developer Profile for CarPlay/Enhanced Siri? I do not see it anywhere in developer.apple.com/download.

I am running the (MFI) CarPlay Tests 2.7 app on my 2 iPhone 7's, each with iOS 15.4.0 installed. Main and Accessory are paired and Main shows it's connected to my Head Unit. When I start the Enhanced Siri Detector Quality test on Main, it shows a popup:

Feature not supported Make sure you have the Accessory Developer Profile installed with Enhanced Siri enabled, and you're running on the latest iOS version. Please, also check if your HeadUnit supports this feature.

I know my HeadUnit supports this feature because I am able to run it when an iPhone 8 with iOS 15.4.0 is set up as Main. I now need to run it on my iPhone 7. I didn't have to set up this profile on the iPhone 8. I have Siri enabled on this iPhone 7 Main.

How do I install Accessory Developer Profile for CarPlay/Enhanced Siri
 
 
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