How would I remove the camera restrictions in the Y axis?

Put this code in LocalScript in StarterCharacterScripts

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

local Camera = {}

function Camera.new()
    local self = setmetatable(
        {},
        {
            __index = function(self, Index)
                if Camera[Index] then
                    return Camera[Index]
                end
            end
        }
    )

    self.CurrentCamera = game.Workspace.CurrentCamera
    self.Character = game.Players.LocalPlayer.Character or game.Players.LocalPlayer.CharacterAdded:Wait()

    self.X = 0
    self.Y = 0

    self.Sensitivity = 0.015
    self.CameraOffset = Vector3.new(0, 3, 12)

    self.IsRightMouseButtonDown = false

    self:Initialize()

    return self
end

function Camera:Initialize()
    self.CurrentCamera.CameraType = Enum.CameraType.Scriptable

    ContextActionService:BindAction(
        "RightClickChanged", 

        function(ActionName, InputState, InputObject)
            self:RightClickChanged(ActionName, InputState, InputObject) 
        end, 

        false, 
        Enum.UserInputType.MouseButton2
    )

    ContextActionService:BindAction(
        "UpdateAngles",

        function(ActionName, InputState, InputObject)
            self:UpdateAngles(ActionName, InputState, InputObject) 
        end,

        false,
        Enum.UserInputType.MouseMovement
    )

    RunService:BindToRenderStep("UpdateCamera", 200, function()
        self:UpdateCamera()
    end)
end

function Camera:RightClickChanged(ActionName, InputState, InputObject)
    if InputState == Enum.UserInputState.Begin then
        IsRightMouseButtonDown = true
    elseif InputState == Enum.UserInputState.End then
        IsRightMouseButtonDown = false
    end
end

function Camera:UpdateAngles(ActionName, InputState, InputObject)
    if IsRightMouseButtonDown then
        UserInputService.MouseBehavior = Enum.MouseBehavior.LockCurrentPosition

        self.X = self.X + (InputObject.Delta.X * -self.Sensitivity)
        self.Y = self.Y + (InputObject.Delta.Y * -self.Sensitivity)
    else
        UserInputService.MouseBehavior = Enum.MouseBehavior.Default
    end
end

function Camera:UpdateCamera()
    self.CurrentCamera.CFrame = CFrame.new(self.Character.HumanoidRootPart.Position) * CFrame.fromEulerAnglesXYZ(0, self.X, 0) * CFrame.fromEulerAnglesXYZ(self.Y, 0, 0) * CFrame.new(self.CameraOffset.X, self.CameraOffset.Y, self.CameraOffset.Z)

    local CameraRay = Ray.new(self.Character.HumanoidRootPart.Position, self.CurrentCamera.CFrame.Position - self.Character.HumanoidRootPart.Position)
    local Ignore = {self.Character}

    local HitPart, HitPosition = game.Workspace:FindPartOnRayWithIgnoreList(CameraRay, Ignore)

    self.CurrentCamera.CFrame = (self.CurrentCamera.CFrame - (self.CurrentCamera.CFrame.Position - HitPosition)) + (self.Character.HumanoidRootPart.Position - self.CurrentCamera.CFrame.Position).Unit
    self.CurrentCamera.Focus = self.CurrentCamera.CFrame
end

return Camera.new()