Examine source code of Mealia

{
  "manifest_version": 3,
  "name": "Mealia",
  "version": "1.3",
  "icons": {
    "16": "icons/logo16.png",
    "48": "icons/logo16.png",
    "128": "icons/logo16.png"
  },
  "permissions": [
    "tabs",
    "cookies",
    "storage",
    "activeTab",
    "scripting",
    "webRequest"
  ],
  "externally_connectable": {
    "matches": [
      "http://localhost:3001/*",
      "https://www.staging.mealia.co.uk/*",
      "https://www.beta.mealia.co.uk/*"
    ]
  },
  "host_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "action": {
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.asda.com/*",
        "https://groceries.asda.com/*",
        "https://www.tesco.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "/*.ttf"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "rish@mealia.co.uk"
    }
  }
}