Hi xips,
To help us assist you, can you let us know more about what happens when you try to use Touch ID? For example, do you receive a specific error? If so, what does the exact error say? That information will help us plan how to proceed.
If Touch ID isn't working on your iPhone, please check out this link, which has some information and suggestions that may help with this issue: If Touch ID isn't working on your iPhone or iPad
If you can't unlock your iOS device using Touch ID, can't enroll a fingerprint, or you're asked to enter your passcode, learn what to do.
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.
Thanks!