FOV circle example:

local mouse = game.Players.LocalPlayer:GetMouse()

local FOVCircle = Drawing.new("Circle")
FOVCircle.Radius = 50
FOVCircle.Color = Color3.fromRGB(255, 170, 0)
FOVCircle.Thickness = 3
FOVCircle.Filled = false

local CircleTbl = {
    Update = function()
        FOVCircle.Position = Vector2.new(mouse.X, mouse.Y+36)
    end
}
table.insert(ESP.Objects, CircleTbl)