Examine source code of show-my-ip

{
  "name": "show-my-ip",
  "description": "View your IP address",
  "version": "1.6",
  "homepage_url": "https://github.com/TwinProduction/show-my-ip",
  "manifest_version": 2,
  "author": "TwinProduction",
  "icons": {
    "16": "data/icon-16.png",
    "32": "data/icon-32.png",
    "64": "data/icon-64.png",
    "128": "data/icon-128.png"
  },
  "browser_action": {
    "default_title": "Display your IP address",
    "default_popup": "data/index.html",
    "default_icon": {
      "16": "data/icon-16.png",
      "32": "data/icon-32.png",
      "64": "data/icon-64.png",
      "128": "data/icon-128.png"
    }
  },
  "permissions": [
    "https://twin.sh/api/v1/ip",
    "http://ip-api.com/line?fields=query",
    "webRequest",
    "clipboardWrite"
  ]
}