How to point naked domain and www to the same Heroku app?

I create a simple Rails app and deployed it to Heroku. This is my app. I use Cloudflare to manage my DNS records and I try to achieve something like this:

This is all my current DNS records inside my Cloudflare:

My problem:

When I go to ordr.my, it's works like I wanted to.But when I go to www.ordr.my, it returns This webpage is not available error (I'm using Chrome browser).

Am I doing any mistakes here?

How to achieve something like inside the image above?

Note:

I did my research by reading Heroku and CloudFlare docs. But I found no luck since I'm not able to understand them very clearly.

Reference:

1. Heroku Custom Domains
2. Cloudflare Zone Apex
3. Cloudflare CNAME Flattening