Drag to Aim , Release To Fire

Hye there i m making a simple Shooting Game but its not like

FPS(First Person) shooting game..

it is simple 2d (Mobile game) where if we touch anywhere on

screen player aim at that point and a Aiming arrow is also

appear and when we release it shoots the bullet....

i know I can make that with the help of OnPointerDown ,

OnDrag , OnPointerUp function but because i m beginer i cant

code that properly i tried but failed every time....
and one more thing bullet has rigidbody so we only have to

addfore in the direction of pointer released plz helpme

out.....

if there is any Video Tutorial availabe similar to my

Problem then plz send me link...

i will be thankfull n appricate u in advance for my help
u can Better understand with photos that i attached what i m

trying to do....