Attempt to concatenate nil with string while using FireServer

Hi! I am trying to send the information of a player-object from the client to the server using FireServer. When I do this, it returns the error ‘attempt to concatenate nil with string’. Here is my code; Any help is great.

-- SERVER

function M.SendData(player, data)
	local succ, err = pcall(function()
		local Data = {
			["embeds"] = { {
				["title"] = player.Name .. "'s application", -- Particular line that errors.

-- CLIENT

Events.Application.SendAppRemote:FireServer(M.Data.AnsweredQuestions) -- Doesn't error. I don't believe that the Data is the problem.

How exactly do you hook up the function to the remote?

SendApplication.OnServerEvent:Connect(function(Player, ...)
	local applicationData = ...
	local character = Player.Character
	local applicationTool = character:FindFirstChild("Application Form")
	--local submittedApplication = ApplicationDataStore:GetAsync(Player.UserId)
	
	character.Humanoid:UnequipTools()
	applicationTool:Destroy()
	--ApplicationDataStore:SetAsync(Player.UserId, true)

	spawn(function()
		M:SendData(Player, applicationData)
	end)
end)

Replace M.SendData(player, data) with this:

function M.SendData(self, player, data)

For more info regarding self, see this post

What CodedError said. It’s because you did:

		M:SendData(Player, applicationData)

Instead of:

		M.SendData(Player, applicationData)

which sends the table (itself) as the first argument when using :