Examine source code of Accept Header Override

{
  "manifest_version": 3,
  "name": "Accept Header Override",
  "description": "This extension overrides the default 'Accept' header to prevent websites from serving lossy WEBP images instead of the original PNG/JPG.",
  "version": "1.0",
  "minimum_chrome_version": "86",
  "browser_specific_settings": {
    "gecko": {
      "id": "accept-header-firefox@miaucake.github.com",
      "strict_min_version": "113.0"
    }
  },
  "permissions": [
    "declarativeNetRequest"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "declarative_net_request": {
    "rule_resources": [
      {
        "id": "ruleset",
        "path": "rules.json",
        "enabled": true
      }
    ]
  }
}