Examine source code of Save to Crates

{
  "name": "Save to Crates",
  "short_name": "Save to Crates",
  "version": "1.12.0",
  "description": "Save music to Crates!",
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "icons": {
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "64": "images/icon64.png",
    "128": "images/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "tagify.min.js",
        "content.js"
      ],
      "css": [
        "tagify.css",
        "content.css"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "tabs",
    "contextMenus",
    "storage"
  ],
  "host_permissions": [
    "*://localhost/*",
    "*://*.bandcamp.com/*"
  ],
  "action": {
    "default_title": "Click to save current page to Crates"
  },
  "commands": {
    "save-to-crates-action": {
      "description": "Save to Crates",
      "suggested_key": {
        "default": "Ctrl+Shift+S",
        "linux": "Ctrl+Shift+S",
        "mac": "Command+Shift+S",
        "windows": "Ctrl+Shift+S"
      }
    }
  },
  "options_page": "options.html",
  "manifest_version": 3,
  "browser_specific_settings": {
    "gecko": {
      "id": "firefox@cratesapp.com"
    }
  }
}