/tests/tools/fixtures/extension-side-panel/manifest.json

{
  "name": "Test Extension Side Panel",
  "version": "1.0.0",
  "manifest_version": 3,
  "permissions": ["sidePanel"],
  "action": {
    "default_title": "Click to open panel"
  },
  "background": {
    "service_worker": "sw.js"
  },
  "side_panel": {
    "default_path": "sidepanel.html"
  }
}