How do I make my Fireball go to where my Mouse points?

local StarPack = game:GetService("StarterPack")
local RepStore = game:GetService("ReplicatedStorage")

StarPack.FireballF.OnServerEvent:Connect(function(plr)
	local char = plr.Character
	local x = RepStore.Fireball:Clone()
	x.Parent = workspace
	x.CFrame = char.UpperTorso.CFrame * CFrame.new(0,0,-4)
	x.CanCollide = false
	local v = Instance.new("BodyVelocity")
	v.Parent = x
	v.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
	v.Velocity = 
end)

local UIS = game:GetService("UserInputService")
local StarPack = game:GetService("StarterPack")
Ammo = 1

UIS.InputBegan:Connect(function(input)
if Ammo == 1 then
	if input.KeyCode == Enum.KeyCode.F then
		StarPack.FireballF:FireServer()
			Ammo = Ammo-1
			wait(2)
			Ammo = 1
		end
	end
end)

The first is the Script, the second is the Local Script v.Velocity should go to where the mouse points

You can use the GetMouse() function to get where the mouse is exactly

you can get the players mouse by doing: local mouse = player:GetMouse() then you can use mouse.hit.p to get the position of your mouse, then you can sent that over to the server.

Within the server you can use the position that you sent to send the fireball towards that direction. To calculate the distance between where your character is and where the fireball needs to go do something like (currentPos- mousePos).magnitude

Hope this helps!