as you see, shadow is blurred. (see the tree's shadow)
What settings should I add?
Mkj6026, I think you should polish the gameObject which stands for the TREE. Because, look at the car. The car's shadow isn't blurred. There is something wrong only with the trees. Try re-implementing your lighting. Or you can also try adding more trees to your scene and see if the problem still persists. If it does, try changing the code of your tree gameObject and check if something's wrong.
I think think your code is correct and there shouldn't be any problem. You can also try testing on another Google Android device.