how to use the finger new

Hi

If Touch ID isn't working on your iPhone, you'll need to follow the steps outlined here, including getting your iPhone serviced if needed: If Touch ID isn't working on your iPhone or iPad - Apple Support

"Where is the Touch ID sensor?

The Touch ID sensor is either in the Home button or—on iPad mini (6th generation) and iPad Air (4th and 5th generation)—the top button. When you follow the steps below, the onscreen instructions will tell you which button to use. If you're not sure, learn which button is which on your iPad.

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

1. Make sure that you have the latest version of iOS or iPadOS.
2. Make sure that your fingers and the Touch ID sensor are clean and dry.* For the Touch ID sensor, use a clean, lint-free cloth to wipe off any dirt or debris.
3. Your finger should cover the Touch ID sensor 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 Touch ID sensor 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 grayed out

"

Cheers.