Examine source code of Sheets Range to Image

{
  "manifest_version": 2,
  "name": "Sheets Range to Image",
  "version": "1.0.1",
  "description": "Export a selected range of cells in Google Sheets as a high-quality PNG (with full emoji support).",
  "author": "safelysound",
  "homepage_url": "https://github.com/safelysound/range-to-image",
  "browser_specific_settings": {
    "gecko": {
      "id": "sheets-range-to-image@safelysound.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icons/icon.svg",
    "96": "icons/icon.svg",
    "128": "icons/icon.svg"
  },
  "permissions": [
    "clipboardRead",
    "clipboardWrite"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://docs.google.com/spreadsheets/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    "icons/icon.svg"
  ]
}