Why does this script error?

local DataStore = game:GetService("DataStoreService"):GetDataStore("List")
key = "list1"

wait(5)

while true do

DataStore:UpdateAsync(key, function(oldValue)
local newValue = oldValue --oldValue might be nil
if game.Workspace.Game.RankUp.Value == true then
newValue = script.Parent.Parent.Parent.Name
end
return newValue
end)

wait(1)

end

Gets this error; Cannot write to DataStore from studio if API access is not enabled. Enable it by going to the Game Settings page.