Lua Cant Create Object

Question

My Code is:

Target = {}
Target.__index = Target

function Target.new(isfound,distance,azimuth_angle,elevation_angle,time_since_detected)
    local instance = setmetatable({},Target)
    instance.isfound = isfound
    instance.distance = distance
    instance.azimuth_angle = azimuth_angle
    instance.elevation_angle = elevation_angle
    instance.time_since_detected = time_since_detected
    return instance
end

function Target:CalculateXY(maxDistance,radius,radarAngle)
    distancePx = (self.distance/maxDistance)*radius 
    x2 = w / 2 + distancePx * math.cos(1.58+radarAngle)
    y2 = h / 2 + distancePx * math.sin(1.58+radarAngle)
    data = {x = x2, y= y2}
    return data
end

function Target:GetIsFound()
    return self.isfound
end

The error message is:

Exception has occurred: attempt to call a nil value (global 'setmetatable')

It is triggered on the Line:

local instance = setmetatable({},Target)

I am Using VS Code with the lua version:

Name: Lua
Id: sumneko.lua
Description: Lua Language Server coded by Lua
Version: 3.5.6
Publisher: sumneko
VS Marketplace Link: https://marketplace.visualstudio.com/items?itemName=sumneko.lua

What could be the issue?