How do i move the players arm so they AIM through the weapon they are looking at?

So i already did some research and didnt come up with many results... animations was something i found. so i tried the roblox animator and made my own animation just to tilt the arm so he "looks" through the gun, The animation wouldnt play

local animation = Instance.new("Animation")
animation.AnimationId = "rbxassetid://745664180"
--tool is my weapon 
local animTrack = tool.Parent.Humanoid:LoadAnimation(animation)
animTrack:Play()    

note that this is inside a LocalScript and is inside a equipped function

Any ideas?

Plus is there a diffrent way of doing this? i rather not have to remake the animation every time its off by a bit.