@ahmedibrah21733 the only way to fix it is by replacing it. Since iFixit does not yet have a guide for this, use something like [link|https://www.youtube.com/watch?v=r4lbC8_O9hs|this video] to get it done. Replacement displays are readily available at many online stores.
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!