Examine source code of uwu.so Uploader

{
  "manifest_version": 2,
  "name": "uwu.so Uploader",
  "description": "Upload image to uwu.so by using context menu.",
  "version": "1.0.1",
  "homepage_url": "https://uwu.so",
  "icons": {
    "48": "icons/48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "activeTab",
    "contextMenus",
    "storage",
    "clipboardWrite",
    "notifications",
    "*://*/*"
  ],
  "browser_action": {
    "default_title": "uwu.so Image Uploader",
    "default_popup": "popup/index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a6aede69-7255-49d1-b897-52f0da56d752}"
    }
  }
}