How can I make a light flash when the cell phone rings?

Watched your video. I don’t have Tasker or Sharptools, but I guess I will be adding them. Have the grand kids the next 24 hours, so I am going to wait. Tasker has a 7 day free trail, so I want to be sure I have time to learn it… thanks for the direction. This looks like it will do just what I need. Thanks