How to deploy Gmail Contextual Gadget on Google Marketplace as App for Gmail?

Question

I have a simple plugin that renders gmail data. I want to deploy on Google Marketplace. I followed this link : https://developers.google.com/gmail/contextual_gadgets

I have uploaded the zip with manifest.json file on chrome developer console. The plugin is available in the marketplace. But when I install and run the plugin it opens the website rather than enabling the plugin on Gmail.

I have entered details into Google Apps Marketplace SDK, defined the email extractors.

I have created the manifest.json file as follows and uploaded to developer console. Below code is just an example, I have mentioned valid values in the JSON.

{
   "manifest_version": 2,
   "name": "My App",
   "short_name": "My App",
   "version": "1.0.0",
   "description": "Desctription................",
   "app" : {
     "launch" : {
        "web_url" : "https://www.myapp.com"
     }
   },
  "icons": {
    "128": "icons/128x128-icon.png",
    "16": "icons/16x16-icon.png"
  },
  "container": ["DOMAIN_INSTALLABLE"],
  "api_console_project_id": "XXXXXXXXXX"
}

The application was published on marketplace. But the plugin is not enabled in my gmail app. Rather it opens the website link. Please guide what is missing in the configuration or in the manifest file.

Thanks in advance!