ServerScriptService.PlayerDSS:40: attempt to index local 'GetLevel' (a nil value) ?

In a script, i've used the DataStoreService, to allow my game to save data. It perfectly works until the use of GetAsync.

Here's the part that doesnt work :

game.Players.PlayerAdded:Connect(function(player)

local plrID = "player_"..player.userId
local playerLevel = DSService:GetDataStore("plrLevel")

local GetLevel = playerLevel:GetAsync(plrID)

level.Value = GetLevel[1] or 1 -- this ain't working. Also, i did put the [1] to every values (GetExp[1] or 0 ; GetStamina[1] or 0 , etc....)

end)