Examine source code of VocaInfo

{
  "manifest_version": 3,
  "name": "VocaInfo",
  "description": "Gives you info on the vocaloid song you're listening to (data from vocadb.net)",
  "version": "1.0",
  "action": {
    "default_popup": "popup.html",
    "default_icon": "extension.png"
  },
  "icons": {
    "48": "extension.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "hi@defualtbox.xyz",
      "strict_min_version": "58.0"
    }
  }
}