You tweened the frame in the StarterGui. You need to tween the frame in the player’s GUI, aka the parent of the LocalScript that you have in there:
local button = script.Parent
local frame = button.Parent.gui -- Repeat parent until it is the shop GUI's gui
button.Activated:Connect(function()
frame:TweenPosition(
UDim2.new(0.5, 0, 0.5, 0),
Enum.EasingDirection.Out,
Enum.EasingStyle.Sine,
2,
true
)
end)