How can I send Mouse.Hit inputs to server scripts?

Hello, I am asking how can I send Mouse.Hit inputs to server scripts. So, I'm trying to make grappling, but it only prints out my string that I put in and doesn't put the attachment inside of the Mouse.Hit.Parent. P.S the grappling needs to go towards the mouse. I have both a localscript and server script.

--Localscript

local mouse = game.Players.LocalPlayer:GetMouse()
local player = game.Players.LocalPlayer
local char = player.Character
local UIS = game:GetService("UserInputService")

UIS.InputBegan:Connect(function(input)
	if input.KeyCode == Enum.KeyCode.E then
		game.ReplicatedStorage.RightGrapple:FireServer(char, mouse)
	end
end)

--Script

game.ReplicatedStorage.RightGrapple.OnServerEvent:Connect(function(char, mouse)
	local grappleright = coroutine.create(function()
		print("weeee we go on hook yey")
		local attachment = Instance.new("Attachment",mouse.Hit.Parent)
		attachment.Position = mouse.Hit
		local magichookthing = char.magixx.Welds.RightContainer:FindFirstChild("magichook")
		local rope = Instance.new("RopeConstraint",magichookthing)
		rope.Attachment0 = magichookthing.Attachment
		rope.Attachment1 = attachment
	end)
	
	coroutine.resume(grappleright)
end)

The help would be appreciated, thanks!

You can't send the mouse to the server, because the raycasting going on is client sided only, so it is a simple fix, just send the mouse.Hit from the client to the server:

local script: (please do this outside of your script, I didn't know you had 2 code blocks until I went to view the source)

local mouse = game.Players.LocalPlayer:GetMouse()
local player = game.Players.LocalPlayer
local char = player.Character
local UIS = game:GetService("UserInputService")

UIS.InputBegan:Connect(function(input)
    if input.KeyCode == Enum.KeyCode.E then
        game.ReplicatedStorage.RightGrapple:FireServer(char, mouse.Hit)
    end
end)

Server script:

game.ReplicatedStorage.RightGrapple.OnServerEvent:Connect(function(char, Hit)
        print("weeee we go on hook yey")
        local attachment = Instance.new("Attachment")
        attachment.Parent = Hit
        local magichookthing = char.magixx.Welds.RightContainer:FindFirstChild("magichook")
        local rope = Instance.new("RopeConstraint")
        rope.Attachment0 = magichookthing.Attachment
        rope.Attachment1 = attachment
	rope.Parent = magichookthing --set parent last
	--you don't need a coroutine.
end)

Since this answers your question, mark it as accepted.