Unable to show a message after plugin activation

<?php
/*
  Plugin Name: Activation
  Description: This display notice message test plugin
  Author: Nanhe Kumar
  Version: 1.0
  Author URI: http://nanhe.in/
 */

class Activation {

    public static function init() {
        add_action('admin_notices', array(__CLASS__, 'text_admin_notice'));
    }

    public static function text_admin_notice() {
        ?>
        <div class="notice notice-success is-dismissible">
            <p> TEST MESSAGE</p>
        </div>
        <?php
    }

}
add_action('init', array('Activation', 'init'));

Your message not showing because your class constructor is not executing you can test through add die in your constructor then you can better understand what is happening.

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