I’ve tried messing wit the setting , completely powering off my phone , but Siri won’t respond when I say hey Siri

Go to your Siri settings and make sure ‘listen for Hey Siri’ is enabled. It will ask you to set up Hey Siri, just follow the instructions on the screen. You might need to disable and re-enable Hey Siri for it to work.

Which iPhone model do you have?

And the iOS version?

Please help me my siri not working