Examine source code of OpenHeader

{
  "manifest_version": 3,
  "name": "OpenHeader",
  "version": "1.0.0",
  "description": "A lightweight open-source extension to modify request and response headers and filter by URL regexes.",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "storage",
    "tabs",
    "declarativeNetRequest"
  ],
  "host_permissions": [
    "*://*/*"
  ],
  "action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    },
    "default_title": "OpenHeader",
    "default_popup": "popup.html"
  },
  "background": {
    "service_worker": "background.js",
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "openheader@kevinchua6",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}