Examine source code of Focus Tabs

{
  "manifest_version": 3,
  "name": "Focus Tabs",
  "version": "1.1",
  "description": "Instant tab switching with global hotkeys",
  "permissions": [
    "tabs",
    "storage",
    "activeTab",
    "notifications"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "focus-tabs@yourdomain.com",
      "strict_min_version": "112.0",
      "data_collection_permissions": {
        "required": [
          "websiteActivity"
        ],
        "optional": []
      }
    }
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "Focus Tabs"
  },
  "commands": {
    "jump-slot-0": {
      "suggested_key": {
        "default": "Alt+0"
      },
      "description": "Jump to tab in slot 0"
    },
    "jump-slot-1": {
      "suggested_key": {
        "default": "Alt+1"
      },
      "description": "Jump to tab in slot 1"
    },
    "jump-slot-2": {
      "suggested_key": {
        "default": "Alt+2"
      },
      "description": "Jump to tab in slot 2"
    },
    "jump-slot-3": {
      "suggested_key": {
        "default": "Alt+3"
      },
      "description": "Jump to tab in slot 3"
    },
    "jump-slot-4": {
      "suggested_key": {
        "default": "Alt+4"
      },
      "description": "Jump to tab in slot 4"
    },
    "jump-slot-5": {
      "suggested_key": {
        "default": "Alt+5"
      },
      "description": "Jump to tab in slot 5"
    },
    "jump-slot-6": {
      "suggested_key": {
        "default": "Alt+6"
      },
      "description": "Jump to tab in slot 6"
    },
    "jump-slot-7": {
      "suggested_key": {
        "default": "Alt+7"
      },
      "description": "Jump to tab in slot 7"
    },
    "jump-slot-8": {
      "suggested_key": {
        "default": "Alt+8"
      },
      "description": "Jump to tab in slot 8"
    },
    "jump-slot-9": {
      "suggested_key": {
        "default": "Alt+9"
      },
      "description": "Jump to tab in slot 9"
    },
    "mark-slot-0": {
      "suggested_key": {
        "default": "Ctrl+Shift+0",
        "mac": "Command+Shift+0"
      },
      "description": "Mark current tab in slot 0"
    },
    "mark-slot-1": {
      "suggested_key": {
        "default": "Ctrl+Shift+1",
        "mac": "Command+Shift+1"
      },
      "description": "Mark current tab in slot 1"
    },
    "mark-slot-2": {
      "suggested_key": {
        "default": "Ctrl+Shift+2",
        "mac": "Command+Shift+2"
      },
      "description": "Mark current tab in slot 2"
    },
    "mark-slot-3": {
      "suggested_key": {
        "default": "Ctrl+Shift+3",
        "mac": "Command+Shift+3"
      },
      "description": "Mark current tab in slot 3"
    },
    "mark-slot-4": {
      "suggested_key": {
        "default": "Ctrl+Shift+4",
        "mac": "Command+Shift+4"
      },
      "description": "Mark current tab in slot 4"
    },
    "mark-slot-5": {
      "suggested_key": {
        "default": "Ctrl+Shift+5",
        "mac": "Command+Shift+5"
      },
      "description": "Mark current tab in slot 5"
    },
    "mark-slot-6": {
      "suggested_key": {
        "default": "Ctrl+Shift+6",
        "mac": "Command+Shift+6"
      },
      "description": "Mark current tab in slot 6"
    },
    "mark-slot-7": {
      "suggested_key": {
        "default": "Ctrl+Shift+7",
        "mac": "Command+Shift+7"
      },
      "description": "Mark current tab in slot 7"
    },
    "mark-slot-8": {
      "suggested_key": {
        "default": "Ctrl+Shift+8",
        "mac": "Command+Shift+8"
      },
      "description": "Mark current tab in slot 8"
    },
    "mark-slot-9": {
      "suggested_key": {
        "default": "Ctrl+Shift+9",
        "mac": "Command+Shift+9"
      },
      "description": "Mark current tab in slot 9"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}