How to get the mouse with filtering enabled on? (In a gun script)

When I run the code locally it works well but when I run it on a server, it does not recognize the mouse. I am pretty new to filtering enabled and I need help. Side note: the damage does not work either.

Local script:

h = script.Parent.Handle


script.Parent.Activated:Connect(function()
	game.ReplicatedStorage.RemoteEvent:FireServer(h)
end)

Server script:

game.ReplicatedStorage.RemoteEvent.OnServerEvent:Connect(function(plr,  handle)
	local m = plr:GetMouse()
	local b = Instance.new("Part",game.Workspace)
	b.Shape = "Ball"
	b.BrickColor = BrickColor.new("Really red")
	b.Size = Vector3.new(1,1,1)
	b.CFrame = CFrame.new(handle.Position, mouse.hit.p)
	local v = Instance.new("BodyVelocity",b)
	v.Velocity = b.CFrame.lookVector * 400
	v.MaxForce = Vector3.new(math.huge,math.huge,math.huge)
	local d = game:GetService("Debris")
	d:AddItem(b, 5)
	b.Touched:connect(function(hit)
		if hit ~= handle then		
			local h = hit.Parent:FindFirstChild("Humanoid")
			if h then
				if h.Parent.Name ~= plr.Name then		
				h:TakeDamage(10)
				end
			end
		end
	end)
end)

I would suggest passing the mouse from the client alongside everything else. To do that, just create another argument in your server script.

I'm calling it "m" since that's what you call the mouse in your script previously

game.ReplicatedStorage.RemoteEvent.OnServerEvent:Connect(function(plr,  handle, m)

& pass it along from the client: (localscript)

local lp = game.Players.LocalPlayer
 game.ReplicatedStorage.RemoteEvent:FireServer(h, lp:GetMouse())

Delete the "local m = plr:GetMouse()" line from your server script.

Your final LocalScript code should look like this:

local h = script.Parent.Handle
local lp = game.Players.LocalPlayer

script.Parent.Activated:Connect(function()
    game.ReplicatedStorage.RemoteEvent:FireServer(h, lp:GetMouse())
end)

And your serverscript code should look like this:

game.ReplicatedStorage.RemoteEvent.OnServerEvent:Connect(function(plr,  handle, m)
   -- we no longer need to use GetMouse(), since it's already passed
    local b = Instance.new("Part",game.Workspace)
    b.Shape = "Ball"
    b.BrickColor = BrickColor.new("Really red")
    b.Size = Vector3.new(1,1,1)
    b.CFrame = CFrame.new(handle.Position, mouse.hit.p)
    local v = Instance.new("BodyVelocity",b)
    v.Velocity = b.CFrame.lookVector * 400
    v.MaxForce = Vector3.new(math.huge,math.huge,math.huge)
    local d = game:GetService("Debris")
    d:AddItem(b, 5)
    b.Touched:connect(function(hit)
        if hit ~= handle then      
            local h = hit.Parent:FindFirstChild("Humanoid")
            if h then
                if h.Parent.Name ~= plr.Name then      
                h:TakeDamage(10)
                end
            end
        end
    end)
end)

Note: I made it pretty copy-paste friendly, and I'm sorry for that. Please read over what I've said and not just copy and paste if it does end up working.