ID touch not working.

Ok. Follow these steps. Try using Touch ID after each step:

1. Make sure that you have the latest version of iOS.
2. Make sure that your fingers and the Home button are clean and dry.* For the Home button, use a clean, lint-free cloth to wipe off any dirt or debris.
3. Your finger should cover the Home button completely, touching the surrounding metal ring. While Touch ID is scanning, you shouldn't tap too quickly or move your finger around.
4. If you're using a case or screen protector, make sure it doesn't cover the Home button or the surrounding ring.
5. Go to Settings > Touch ID & Passcode and make sure that iPhone Unlock or iTunes & App Store is on, and that you've enrolled one or more fingerprints.
6. Try enrolling a different finger

Still not working?

If the previous steps didn't help, you see "Failed—unable to complete Touch ID setup", or either of the following happen when you go to Settings > Touch ID & Passcode, take your device to an Apple Retail Store or Apple Authorized Service Provider, or contact Apple Support:

• You can't turn on Touch ID
• Touch ID is dimmed or greyed out

You might need to enter your passcode or Apple ID instead of using Touch ID in these situations:

• You just restarted your device
• Your fingerprint isn't recognized five times in a row
• You haven't unlocked your device in more than 48 hours 
• You just enrolled or deleted fingerprints
• You're trying to open Touch ID & Passcode in the Settings menu
• You used Emergency SOS.

Thanks

Follow these steps:

1. Go to Settings > Touch ID & Passcode
2. Remove your existing fingerprint, then press Add a Fingerprint
3. Touch the Home button with your finger – but don't press. Hold it there until you feel a quick vibration, or until you're asked to lift your finger.
4. Continue to lift and rest your finger slowly, making small adjustments to the position of your finger each time.
5. The next screen asks you to adjust your grip. Hold your device as you normally would when unlocking it, and touch the Home button with the outer areas of your fingertip, instead of the centre portion that you scanned first.
6. If you have trouble enrolling one finger, try another. Still need help setting up Touch ID? 

Thanks