I am following the guidelines as described here
https://developers.google.com/gmail/schemas/reference/one-click-action
But It\'s just wont appear for me. As desc
If you check the email headers, I'd expect that no DKIM/SPF signature can be found, and that is required even for self-testing. Without the signature, anyone can spoof your email address and send you unwanted email with actions.
You have to be approved by Google first, in order for it to work.
To do this:
Send your validated schema-containing email to a special google email address (use this tool: https://www.google.com/webmasters/markup-tester/u/0/) ... then:
Fill out the "Gmail Schema Whitelist Request" form that describes your website and what you intend to do with the one-click action. Here's the form: https://docs.google.com/forms/d/1PA-vjjk3yJF7MLPOVKbIz3MBfhyma2obS8NIZ0JYx8I/viewform?pli=1&fbzx=-1177483801701354615