How do you store a collection of objects in a data store dictionary?

I'm currently attempting to make an adventure game in Roblox; a one like Roblox Adventure 3: Rise of Nobeesi. I'm not really having problems (except trying to make a level fun) except for the DataStore. Previously, it was totally broken, because the thing didn't save/load-- but I fixed it. Unfortunately, there's still a glitch in saving. Loading works; but saving doesn't (i tested it by setting the data manually in the command bar). I found out that saving doesn't work because it can't store dictionaries inside the data store dictionary. How did Polyhex did it? Maybe he had to write like a billion items to check whether a certain Token was collected, but I don't want to do that; it's too complicated and long. How do I store a collection of objects in a DataStore dictionary, then?

For extra proof and comprehension, here is my DataStoreService module script:

local DataModule = {}

local DataStoreService = game:GetService('DataStoreService')
local playerData = DataStoreService:GetDataStore('PlayerData')
local sessionData = {}

local function retry(func)
	local s, data, tries = true, nil, 0
	repeat
		tries = tries + 1
		s, msg = pcall(function()
			data = func()
		end)
		
		if not s then wait(1) end
	until tries == 3 or s
	
	if not s then
		warn('Datastore failure: ' .. msg)
	end
	
	return s, data
end

local function setStats(player)
	local data = sessionData[player]
	local PlayerData = game.ReplicatedStorage.PlayerData[player.Name]
	data.stars = PlayerData.Stars.Value
	data.coins = PlayerData.Coins.Value
	data.weapons = PlayerData.Weapons:GetChildren()
	data.collectedStars = PlayerData.CollectedStars:GetChildren()
end

local function save(player)
	return retry(function()
		return playerData:SetAsync(player.UserId, sessionData[player])
	end)
end

local function load(player)
	return retry(function()
		return playerData:GetAsync(player.UserId)
	end)
end

local function autosave()
	while wait(30) do
		for player, data in pairs(sessionData) do
			setStats(player)
			save(player)
		end
	end
end

local function loadToGame(player)
	local data = sessionData[player]
	local PlayerData = game.ReplicatedStorage.PlayerData[player.Name]
	PlayerData.Stars.Value = data.stars
	PlayerData.Coins.Value = data.coins
	table.foreach(data.weapons, function(_, child)
		child:Clone().Parent = PlayerData.Weapons
		child:Clone().Parent = player:WaitForChild('Backpack')
	end)
	table.foreach(data.collectedStars, function(_, child)
		child:Clone().Parent = PlayerData.CollectedStars
	end)
end

local function setup(player)
	local s, data = load(player)
	if not s then
		sessionData[player] = false
	else
		if data then
			sessionData[player] = data
			loadToGame(player)
			print('Loaded data for '..player.Name)
		else
			sessionData[player] = {stars = 0, coins = 0, collectedStars = {}, weapons = {}}
			print('No data found, creating data for '..player.Name)
		end
	end
end

game.Players.PlayerAdded:Connect(setup)

game.Players.PlayerRemoving:Connect(function(player)
	setStats(player)
	wait()
	print(sessionData[player].coins)
	save(player)
	wait()
	sessionData[player] = nil
end)

spawn(autosave)

print('DataStoreService module loaded.')

return DataModule

It is not the dictionary that is the problem; you just can’t save Instances inside DataStores. The best way to get around this is by saving the names of the weapons, and when loading, clone a weapon with the same name from ServerStorage and giving it to the player. For the collected stars, you could assign each star to a number, and just save a table of the star numbers that the player has collected.