Plugin Help Arrow Damage help

I want to code a plugin that if i press left click it will shoot an arrow [left click with bow], and when the arrow
will be on ground, he will made some damage all player from 5 block radius.
This is what i made:

now it is shooting the arrow but i dont know the code that when it is on the ground it will do damage to player
of 5 radius block

tnx for all helpers.