Examine source code of Wplace Tracer

{
  "name": "Wplace Tracer",
  "description": "Overlay images on wplace.live to help in drawing by tracing on them",
  "version": "1.2.0",
  "manifest_version": 3,
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "assets/logo16.png",
    "48": "assets/logo48.png",
    "128": "assets/logo128.png"
  },
  "action": {
    "default_title": "Wplace Tracer",
    "default_icon": "assets/logo128.png"
  },
  "sidebar_action": {
    "default_panel": "popup.html",
    "default_title": "Wplace Tracer",
    "default_icon": "assets/logo128.png"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://wplace.live/*"
      ],
      "js": [
        "contentScript.js"
      ],
      "css": [
        "contentStyle.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "@wplace-tracer.zaifsenpai",
      "strict_min_version": "109.0"
    }
  }
}