[SOLVED] Inputting more than one letter at the same time?

I'm making a Hangman game, and I want to make sure that if there are multiple letters that are the same in the string, I want to input them in their desired locations. However, only the first found is inputted.

local words = {
	"airplane", "vehicle", "house", "machine", "castle", "airport", "medieval", "recovery", "hospital", "police",
	"animal",
}

local tries = 6 -- each body part

local slots = {}

local function chooseWord()
	local word = words[math.random(1, #words)]
	return word
end

local function generateSlots(length) -- based on word's length
	for i = 1, length do
		local slot = script.Slot:Clone()
		slot.Name = "Slot"..i
		table.insert(slots, slot)
		slot.Parent = script.Parent.Slots
	end
	
	for x = 1, #slots do
		slots[x].Position = UDim2.new(slots[x].Position.X.Scale + 0.05, 0, 0.68, 0)
	end
end

local function inputLetter(word, letter)
	print(string.match(word, letter))
	local pos = lookForLetter(word, letter)
	slots[pos].Letter.Text = string.upper(letter)
end

function lookForLetter(word, letter) -- this is the problem of my question
	local position = string.find(word, letter, 0)
	return position
end

play.TextButton.MouseButton1Down:Connect(function()
	play.Visible = false
	title.Visible = false
	back.Visible = true
	
	-- Tweening stuff
	infinite:TweenPosition(UDim2.new(0.5, 0, 0.42, 0), "Out", "Sine", 0.5)
	timed:TweenPosition(UDim2.new(0.5, 0, 0.3, 0), "Out", "Sine", 0.5)
	timerImage:TweenPosition(UDim2.new(0.64, 0, 0.3, 0), "Out", "Sine", 0.5)
	singleplayer:TweenPosition(UDim2.new(0.5, 0, 0.12, 0), "Out", "Sine", 0.5)
	
	infinite.MouseButton1Click:Connect(function()
		infinite.Position = UDim2.new(0.5, 0, 4, 0)
		timed.Position = UDim2.new(0.5, 0, 4, 0)
		timerImage.Position = UDim2.new(0.64, 0, 4, 0)
		singleplayer.Position = UDim2.new(0.5, 0, -4, 0)
		
		local pickedWord = chooseWord()
		print("Word: "..pickedWord)
		generateSlots(string.len(pickedWord))
		letters:TweenPosition(UDim2.new(0, 0, 0, 0), "Out", "Sine", 0.5)
		
		for _, letter  in pairs(letters:GetChildren()) do
			letter.MouseButton1Down:Connect(function()
				print(string.match(pickedWord, string.lower(letter.Text)))
				if string.lower(letter.Text) == string.match(pickedWord, string.lower(letter.Text)) then
					inputLetter(pickedWord, string.lower(letter.Text))
				end
			end)
		end
	end)
end)