If your iPhone Touch ID is not working, try these steps to fix it:
1. Go to Settings > Touch ID & Passcode > Enter your Passcode. Then turn off the iTunes & App Store. Reboot your iPhone. Go back to Touch ID & Passcode in Settings and turn iTunes & App Store back on. Tap on Add a Fingerprint to add another fingerprint.
2. Remove and re-add fingerprints: Settings > Touch ID & Passcode > Enter the passcode of your device > Scroll down to find fingerprints. Tap on the fingerprint, which you want to delete and then Tap on Delete.
3. During the registration process, make sure your finger surface gets scanned and try the different angle.
4. If your finger is wet or there is liquid on your iPhone, you need to dry both your finger and your home button.
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