How can I change this script into a GUI? localscript question

I was doing a map voting tutorial and I'm trying to change it to where instead of it being parts on the floor that you step on to vote I was trying to change it to where you vote with a button.

here is the script:

--Player--
local player = game.Players.LocalPlayer
local char = player.Character or player.CharacterAdded:wait()
local gui = player:WaitForChild("PlayerGui")
local ui= gui:WaitForChild("ui")

--Assets--
local rep = game.ReplicatedStorage
local assets = rep.Assets

--Maps--
local maps = assets.Maps

--Signals--
local signals = assets.Signals
local event = signals.Event
local fevent = signals.FEvent

--Game Variables--
local Game = game.StarterGui.Game
local stats = Game.Stats

--Static Variables--
local vars = {
    currentVote=nil;
    services={};
}

--Primary Events--
event.OnClientEvent:connect(function(variables)
    if variables.reason == "startVoting" then
        table.insert(vars.services, game:GetService("RunService").RenderStepped:connect(function()
            local ray = Ray.new(char.PrimaryPart.CFrame.p, Vector3.new(0.-1000.0))
            local object = workspace:findPartOnRay(ray, char, false, false)
            if object and object.Name:match("VotingButton") then
                local votingGUINum = tonumber(object.Name:match("%d+"))
                if vars.currentVote==nil then
                    vars.currentVote = votingGUINum
                    event:FireServer({reason="voteOnMap"; itemNum=votingGUINum;})
                elseif vars.currentVote~=votingGUINum then
                    vars.currentVote = votingGUINum
                    event:FireServer({reason="voteOnMap"; itemNum=votingGUINum;})
                end
            elseif vars.currentVote~=nil then
                vars.currentVote=nil
                event:FireServer({reason="removeFromVote"})
            end
        end))
    elseif variables.reason == "endVoting" then
        for a,b in pairs(vars.services) do
            b:disconnect()
        end
        vars.services= {}
    end
end)

on line 33 and 34 the:

        local ray = Ray.new(char.PrimaryPart.CFrame.p, Vector3.new(0.-1000.0))
        local object = workspace:findPartOnRay(ray, char, false, false)

I think this is the issue, this is what detects parts on the map to change text on the part's surface GUI, I changed the parts into GUI's and put them into the StarterGUI with a button to vote, it doesn't seem to work but there is no output error, so I am assuming that this is the error.

If you know how to fix this please reply ! thank you.