Then type in your passcode and tap "Add Fingerprint" to register your own fingerprint.
Then you will get instructions like you need to follow in order to add your fingerprint.
Now Place your finger on the home button and make sure that the entire ring is covered. make sure that your finger is dry.
When you see the ridges of a fingerprint on the screen after that place the same finger on the sensor repeatedly until the fingerprint illustration is filled up completely.
Next step, capture the portion of your fingerprint by adjusting your grip and keeping your finger in place on the sensor.
This is very important in case you hold your phone at an unusual angle, and the sensor detects a different area of your fingerprint.
Once you complete this process, just tap "Continue," and you will see the Touch ID & Passcode screen again.
Now you can then customize what you want to use to unlock your phone, Apple Pay, and Apple Wallet, purchase on the iTunes or App Store,and fill in your passwords.
You can add another fingerprint to the system if you want. Go to "Add a Fingerprint" and follow the instructions.
Now next time when you use your iPhone, you will see the Touch ID message. Just place your finger on the home button, and it will unlock your phone in seconds.
Remember Apple iPhones are not the only ones that are equipped with the Touch ID feature. Apple has also rolled out the feature to its other devices, like iPads.
If you want to settouch id on iPad than follow same process.
The process of activating the Touch ID feature on iPads is similar to that of iPhones. Just open the Settings and tap "Touch ID & Passcode," then enter your passcode.