Why is my fingerprint sensor not working

@michaelakerele first you need to check in settings to see if your fingerprint sensor shows up. If it doesn't it's a hardware issue. and indicates a failed senor. IF it does, you want to start your phone in safe mode and see if it works in that mode. If so, you have a 3rd party App that prevents your fingerprint sensor from working. Delete those Apps until you find the one that interferes. To get into safe mode, turn the phone off, power it on, and hold the Volume Down button when the Tecno logo appears. This disables third-party apps to fix system errors. Let us know what you find out.