How to save data when the player leaves?

Heres the script that i have but when i print the datastore i get nil:

Script:

Data = game:GetService("DataStoreService"):GetDataStore("BlastOffMoons")
JSON = game:GetService("HttpService")
Tycoon = ''
local base
local corner
local placedItems = {}
game.Players.PlayerAdded:connect(function(Player)
    repeat wait(1) until Player.Character
    repeat wait() until workspace.TestTycoon.Owner.Value ~= ''
    if workspace.TestTycoon.Owner.Value == Player.Name then
        Tycoon = workspace.TestTycoon
    end
    local plrData = Data:GetAsync(Player.UserId)
    print(plrData)
    if plrData then
    for i, Object in pairs(game:GetService("ReplicatedStorage").GameItems:GetChildren()) do
        for e, Data in pairs(plrData:GetChildren()) do
            if Object.Name == Data[1] then
                local newObject = Object:Clone()
                newObject.Parent =  Tycoon.TestItems
                local location = tonumber(Data[2],Data[3],Data[4])
                newObject:SetPrimaryPartCFrame(location)
            end
        end
    end
    end
end)

game.Players.PlayerRemoving:connect(function(plr)
    if workspace.TestTycoon.Owner.Value == plr.Name then
        Tycoon = workspace.TestTycoon
        base = Tycoon.Base
        corner = Tycoon.Base.Position - (Tycoon.Base.Size/3)
        print(corner)
    end
    local playerData = {
    Money = plr.Money.Value,
    Placed = {['itemPositions:'] = {}}
    }
    Tycoon = workspace.TestTycoon
    for i, v in pairs(Tycoon.TestItems:GetChildren()) do
        print(v.ClassName)
        if v:IsA('Model') then
            table.insert(playerData.Placed["itemPositions:"], {v.Name, v.PrimaryPart.Position.x,v.PrimaryPart.Position.y, v.PrimaryPart.Position.z})
        print(JSON:JSONEncode(playerData))
        Data:SetAsync(plr.UserId, playerData)
        end
    end
end)