How to increase maxhealth?

ok so im trying to make it so the higher your defense stat the more health you have, the part im stuck on is the server script. I have no idea on what to put here so any tips and advice would be great.

local event = game.ReplicatedStorage:WaitForChild("Def")


event.OnServerEvent:Connect(function(player)
    --change INT VALUE here
end)

This is where my Defense stat is stored if that helps

local Stats = player:WaitForChild("Stats")
local Strength = Stats:FindFirstChild("Defense")

local event = game.ReplicatedStorage:WaitForChild("Def")


event.OnServerEvent:Connect(function(player)
	local Stats = player:WaitForChild("Stats")
	local Strength = Stats:FindFirstChild("Defense")
	local humanoid = player.Character and player.Character:FindFirstChild("Humanoid")
	humanoid.MaxHealth = Strength*ratioofstrengthtomaxhealth
end)

local event = game.ReplicatedStorage:WaitForChild("Def")
local DefaultHealth = 10

event.OnServerEvent:Connect(function(player)
local Stats = player:WaitForChild("Stats")
local Strength = Stats:FindFirstChild("Defense")
local char = plr.Character or plr.CharacterAdded:wait()
if char then
local hum = char:FindFirstChild("Humanoid")
if hum then
hum.MaxHealth = DefaultHealth * Strength.Value
end
end
end)