To turn off Siri on your iPhone, you can follow these steps:
1. Go to the Settings app on your iPhone.
2. Scroll down and tap on "Siri & Search".
3. Toggle off the switch next to "Listen for 'Hey Siri'" if you want to disable the "Hey Siri" feature, which activates Siri when you say the phrase "Hey Siri".
4. Toggle off the switch next to "Press Side Button for Siri" if you want to disable the ability to activate Siri by pressing and holding the side button (or Home button on older models) on your iPhone.
5. If you want to completely disable Siri, you can toggle off the switch next to "Allow Siri When Locked". This will prevent Siri from being accessed when your iPhone is locked.
6. After making your desired changes, exit the Settings app. Siri is now turned off based on the settings you've chosen.
Keep in mind that disabling Siri may limit some of the features and functionalities available on your iPhone, as Siri is deeply integrated into iOS. If you ever want to re-enable Siri, you can simply go back to the Siri & Search settings and toggle the switches back on.