How to detect distance from player to object?

This is the current method im using. I'm trying to make a door you have to click "E" to open but I want it so you have to be in range of that door. I am current being faced with the error: "Workspace.Mdoor.Union.Script:5: bad argument #2 to '?' (Vector3 expected, got Object)"

The scripts are below. If anyone knows what im doing wrong and can help me that would be nice :D

Class: LocalScript

local UserInputService = game:GetService("UserInputService")
local rs = game:GetService("ReplicatedStorage")
local r = rs.Remotes:WaitForChild("DoorOpen1")
local plr = game.Players.LocalPlayer
local character = plr.Character or plr.CharacterAdded:Wait()
local HRP = character:WaitForChild("HumanoidRootPart").Position

local function key(inputObject, gameProcessed)
	if inputObject.KeyCode == Enum.KeyCode.E then
		r:FireServer(HRP)
	end
end

UserInputService.InputBegan:Connect(key)

Class: Script

local rs = game:GetService("ReplicatedStorage")
local r = rs.Remotes:WaitForChild("DoorOpen1")

r.OnServerEvent:connect(function(HRP)
	if (script.Parent.Position - HRP).magnitude <= 3 then
		print(r.Name.. " was fired!")
		local door = game.Workspace.Mdoor:WaitForChild("Union")
		local hinge = game.Workspace.Mdoor:WaitForChild("Hinge")
	
		local hingep = hinge.Position

		for i = 1, 120 do
			door.CFrame = CFrame.new(hingep)* CFrame.Angles(0,math.rad(i),0) * CFrame.new(0.294,0,2.89500)
			wait()

		end
	end
end)