Examine source code of Timocall

{
  "icons": {
    "16": "icon16.plasmo.192fd1f9.png",
    "32": "icon32.plasmo.4d28be0c.png",
    "48": "icon48.plasmo.8337b32e.png",
    "64": "icon64.plasmo.c5fef9ed.png",
    "128": "icon128.plasmo.20a0583f.png"
  },
  "manifest_version": 2,
  "browser_action": {
    "default_icon": {
      "16": "icon16.plasmo.192fd1f9.png",
      "32": "icon32.plasmo.4d28be0c.png",
      "48": "icon48.plasmo.8337b32e.png",
      "64": "icon64.plasmo.c5fef9ed.png",
      "128": "icon128.plasmo.20a0583f.png"
    },
    "default_popup": "popup.html"
  },
  "version": "1.4",
  "author": "timocallextension@gmail.com",
  "name": "Timocom call",
  "description": "Helps users to efficiently use the application and speed up the work",
  "background": {
    "scripts": [
      "background.806a2724.js"
    ]
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://my.timocom.com/*",
        "file:///home/karlosos/Dev/timocom/timocom-offline/PL%20%E2%9E%94%20wszystkie%20kraje.html"
      ],
      "js": [
        "email.066dff88.js"
      ],
      "css": []
    },
    {
      "matches": [
        "https://my.timocom.com/*",
        "file:///home/karlosos/Dev/timocom/timocom-offline/PL%20%E2%9E%94%20wszystkie%20kraje.html"
      ],
      "js": [
        "voip-call.cb079153.js"
      ],
      "css": []
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{5113545c-12fe-4cc0-a43c-ee7262cc8b57}"
    }
  }
}