My AirPod pros will not respond to hey Siri. I have IphoneXR

Hello,

Start here: go to Settings > Siri & Search. Is "Hey Siri" on? "Allow Siri When Locked?"

Then see the Siri references in this link:

Connect and use your AirPods and AirPods Pro - Apple Support

If no help, does "Hey Siri" work on your phone directly without AirPods?

Do the AirPods microphones work otherwise. Test with Voice Memos.

Good luck.