Create script 

local player = game.Players.LocalPlayer
local character = player.Character or player.CharacterAdded:Wait()
local humanoid = character:WaitForChild("Humanoid")
-- Coloque isso em um LocalScript (StarterPlayer > StarterPlayerScripts)

local player = game.Players.LocalPlayer
local flying = false
local speed = 50

local UIS = game:GetService("UserInputService")
local RunService = game:GetService("RunService")

local bodyGyro
local bodyVelocity

UIS.InputBegan:Connect(function(input, processed)
	if input.KeyCode == Enum.KeyCode.F and not processed then
		flying = not flying
		local character = player.Character
		local humanoidRootPart = character:WaitForChild("HumanoidRootPart")

		if flying then
			bodyGyro = Instance.new("BodyGyro", humanoidRootPart)
			bodyVelocity = Instance.new("BodyVelocity", humanoidRootPart)

			bodyGyro.P = 9e4
			bodyGyro.MaxTorque = Vector3.new(9e9, 9e9, 9e9)
			bodyGyro.CFrame = humanoidRootPart.CFrame

			bodyVelocity.Velocity = Vector3.zero
			bodyVelocity.MaxForce = Vector3.new(9e9, 9e9, 9e9)

			RunService:BindToRenderStep("Flying", Enum.RenderPriority.Input.Value, function()
				local camCF = workspace.CurrentCamera.CFrame
				bodyVelocity.Velocity = camCF.LookVector * speed
				bodyGyro.CFrame = camCF
			end)
		else
			if bodyGyro then bodyGyro:Destroy() end
			if bodyVelocity then bodyVelocity:Destroy() end
			RunService:UnbindFromRenderStep("Flying")
		end
	end
end)