"create a roblox script where if a exploiter trys to fly it will kick them"

-- server script (ServerScriptService) 
local Players = game:GetService("Players")

local function checkExploit(player)
    local character = player.Character
    if character then
        local humanoidRootPart = character:FindFirstChild("HumanoidRootPart")
        local humanoid = character:FindFirstChild("Humanoid")
        if humanoidRootPart and humanoid then
            local velocity = humanoidRootPart.Velocity
            local speed = math.sqrt(velocity.X^2 + velocity.Y^2 + velocity.Z^2)
            if speed > humanoid.WalkSpeed * 1.5 then
                player:Kick("Flying exploit detected.")
            end
        end
    end
end

local function onPlayerAdded(player)
    player.CharacterAdded:Connect(function(character)
        character.HumanoidRootPart:GetPropertyChangedSignal("Velocity"):Connect(function()
            checkExploit(player)
        end)
    end)
end

Players.PlayerAdded:Connect(onPlayerAdded)
for _, player in ipairs(Players:GetPlayers()) do
    onPlayerAdded(player)
end