"script for an existing nonvisible ui that makes it fade in and swipe up when the player gains coins, showing how many coins they gained, for 2 seconds and then fade out"

-- local script 
local TweenService = game:GetService("TweenService")
local Players = game:GetService("Players")

local player = Players.LocalPlayer
local coinsGainedUI = script.Parent.CoinsGainedUI
local coinsGainedText = coinsGainedUI.CoinsGainedText

coinsGainedUI.Visible = false

local function showCoinsGained(oldValue, newValue)
    local coinsGained = newValue - oldValue
    coinsGainedText.Text = "+" .. tostring(coinsGained) .. " Coins"

local fadeInInfo = TweenInfo.new(0.5, Enum.EasingStyle.Linear, Enum.EasingDirection.In)
    local fadeOutInfo = TweenInfo.new(0.5, Enum.EasingStyle.Linear, Enum.EasingDirection.Out, 0, false, 1.5)
    local swipeUpInfo = TweenInfo.new(2, Enum.EasingStyle.Linear, Enum.EasingDirection.InOut)

local fadeIn = TweenService:Create(coinsGainedUI, fadeInInfo, {Visible = true, BackgroundTransparency = 0.5})
    local swipeUp = TweenService:Create(coinsGainedUI, swipeUpInfo, {Position = coinsGainedUI.Position + UDim2.new(0, 0, -0.1, 0)})
    local fadeOut = TweenService:Create(coinsGainedUI, fadeOutInfo, {Visible = false, BackgroundTransparency = 1})

fadeIn:Play()
    fadeIn.Completed:Wait()
    swipeUp:Play()
    swipeUp.Completed:Wait()
    fadeOut:Play()
end

player.leaderstats.Coins:GetPropertyChangedSignal("Value"):Connect(showCoinsGained)