I need help with setting a value with a database can anyone help?

Module

local PlayerStatManager = {}

local SessionData = {}

function PlayerStatManager:SetStat(player, statName, TextLable)
	TextLable.Text = SessionData[player][statName]
end

Script

local PlayerStatManager = require(game.ServerStorage.PlayerStatManager)
--
local PlayerGui = game:GetService('PlayerGui')
local Message = PlayerGui:WaitForChild('Message')
local Message_Hold = Message:WaitForChild('Message_Hold')
local Message_Text = Message_Hold:WaitForChild('Message_Text')
--
game.Players.PlayerAdded:connect(function(player)
	PlayerStatManager:SetStat(player, 'Money', Message_Text)
end

Can anyone help me with this?