Examine source code of Tabswitcher

{
  "action": {
    "default_title": "Tabswitcher"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "tabswitcher@oddsquat.org",
      "strict_min_version": "110.0"
    }
  },
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "F2"
      }
    }
  },
  "description": "The musthave extension for a mouse-free Firefox experience",
  "homepage_url": "https://github.com/He4eT/tabswitcher",
  "manifest_version": 3,
  "name": "Tabswitcher",
  "permissions": [
    "tabs",
    "sessions"
  ],
  "version": "1.1.1"
}