Custom Button in CustomSiteConfig

Silverstripe Version:


Hey guys,
anyone some ideas or startingpoints for me for adding a custom button or action in a custom siteconfig extension? If it is possible it would be great if I could add that button after some fields in the fieldlist area. I need this for sending a request to a newsletter service for getting an auth. token.

Every idea, link or sources to read and learn would be Great!! Thank you!!
Here is what I already tried:

        - CleverReachExtension

In my config.yml

FormAction::create('loginCleverReach', 'Login'),

In my CustomSiteConfig updateCMSFields function. And this is my extension class:


class CleverReachExtension extends LeftAndMainExtension {

    private static $allowed_actions = array(

    public function loginCleverReach()