Examine source code of RiverWatch

{
  "manifest_version": 3,
  "name": "RiverWatch",
  "version": "1.0.3",
  "description": "Near real-time NOAA river stage levels, streamflow rates, and 3-day hydrograph trends.",
  "browser_specific_settings": {
    "gecko": {
      "id": "riverwatch@riverwatch.app",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "storage",
    "alarms"
  ],
  "host_permissions": [
    "https://api.water.noaa.gov/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "RiverWatch",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  }
}