How to i make a script handler with timer?

I couldn't make a remote event handler with timer. My script is that right now. I want the handler to see when the remote is fired and then it will give me some stats. After that i want it to make a timer in the touched part. I want the timer to -1 every one second. And if the timer is done it will return to normal text. Also if i try to play with it my game crashes. Theres my script right now.

local dab = false
local ReplicatedStorage = game:GetService("ReplicatedStorage")
local touchedEvent = ReplicatedStorage.Events:WaitForChild("getgift")
    local function onTouchedEventFired(player)
        local G = player.Gifts
        local MG = player.MaxGifts
        if dab == false then
            dab = true
            G.Value = MG.Value
            game.Workspace.getgift.CustomPlayerTag.PlayerName.TextColor3 = Color3.fromRGB(255, 0, 0)
            game.Workspace.getgift.CustomPlayerTag.PlayerName.Text = 60
            local timer = Instance.new("NumberValue", game.Workspace.getgift)
            timer.Name = "timer"
            timer.Value = 60
            while true do
            game.Workspace.getgift.timer.Changed:Connect(function()
                game.Workspace.getgift.CustomPlayerTag.PlayerName.Text = timer.Value
                wait(1)
            end)
        end
        while true do
            timer.Value = timer.Value - 1
        end
        while true do
            if timer.Value <1 then
                game.Workspace.getgift.CustomPlayerTag.PlayerName.Text = "GET GIFTS"
                game.Workspace.getgift.CustomPlayerTag.PlayerName.TextColor3 = Color3.fromRGB(255, 213, 0)
            end
        end
    end
end
touchedEvent.OnServerEvent:Connect(onTouchedEventFired)