Examine source code of Devyce Softphone Extension

{
  "manifest_version": 3,
  "browser_specific_settings": {
    "gecko": {
      "id": "support@devyce.co.uk",
      "strict_min_version": "58.0"
    }
  },
  "name": "Devyce Softphone Extension",
  "description": "Extend the capabilities of the Devyce Softphone, including click to call and call control across tabs.",
  "version": "0.13.2",
  "permissions": [
    "tabs",
    "webNavigation"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "exclude_matches": [
        "http://localhost:3000/*",
        "https://softphone.devyce.io/*"
      ],
      "js": [
        "assets/js/iframe.js"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "http://localhost:3000/*",
        "https://softphone.devyce.io/*"
      ],
      "js": [
        "assets/js/softphone.js"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "exclude_matches": [
        "http://localhost:3000/*",
        "https://*.devyce.io/*"
      ],
      "js": [
        "assets/js/links.js"
      ],
      "run_at": "document_end",
      "css": [
        "assets/css/devyceStyles.css"
      ],
      "all_frames": true
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "/assets/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "background": {
    "service_worker": "assets/js/background.js",
    "scripts": [
      "assets/js/background.js"
    ]
  },
  "action": {
    "default_icon": {
      "16": "assets/imgs/logo16.png",
      "24": "assets/imgs/logo24.png",
      "32": "assets/imgs/logo32.png"
    }
  }
}