Chrome Extension: Getting error: Unrecognized manifest key 'start_url'

[Alanna MacNevin]

I posted a question to stackoverflow and then I found this group

See: https://stackoverflow.com/questions/50744141/chrome-extension-getting-error-unrecognized-manifest-key-start-url

Working on a Chrome extension and creating a manifest.json file

Based on the Chrome documents the "start_url" exists (and is documented) https://developers.google.com/web/fundamentals/web-app-manifest/#start-url

But I'm getting the error "Unrecognized manifest key 'start_url'". Obviously, I can remove that key and 'fix' the error, but I want the ability to 'tell the browser where your application should start when it is launched...direct the user straight into your app, rather than a product landing page. Think about the what the user will want to do once they open your app, and place them there" (which is what the start_url key is supposed to do)

Is there another way to achieve this that isn't documented? Is my syntax wrong somehow?

     

{
        "start_url": "/start", // the page I want the app to open on
        "manifest_version": 2,
        "name": "My Extension",
        "description": "A fantastic extension",
        "short_name": "Extension",
        "version": "1.0",
        "background": {
          "scripts": [
            "events.js"
          ],
          "persistent": true
        },
          "browser_action": {
          "default_popup": "index.html",
          "default_title": "Extension"
        },
        "content_scripts": [
          {
            "matches": ["*://*/*"],
            "css": [],
            "js": ["content.js"]
          }
        ]
     }