@segunotunaiya first make sure that it is enabled in the settings menu. Go to Biometric, then Fingerprints and setup your prints. If the reader is not even being seen, then it is possible that you have a failed reader. To replace it, you can use something like [link|https://www.youtube.com/watch?v=P1vC4YbNxBo|this video] as your guide.
Now, if that does not repair your fingerprint reader, you will have to do a deeper check. Here is the Samsung flowchart for the Fingerprint Sensor not working
[image|3024607]
Use the search function of your PDF reader to locate the components to be checked, from this document [document|30516]
While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.
***Repair is War on Entropy!***