I am new to wordpress/woo plugin development I want to change icon of woocommerce_product_write_panel_tabs I think its automatically added.

<?php
/*
Plugin Name: Payment Plan
Plugin URI:
Description: Monthly payment plan 
Version: 1.0
Author: DIlshod
Author URI: itexpress.uz
*/
/**
* Payment Plan
*/


class PaymentPlan {

    function __construct() {
        add_action( 'woocommerce_product_write_panel_tabs', array($this,'monthly_payment_tabs_on_product_publish' ));
    }

   


    function monthly_payment_tabs_on_product_publish(){
        ?>
        <li class="custom_tab">
            <a href="#custom_tab">
                <?php _e('Monthly Plan', 'MPP'); ?>
            </a>
        </li>
        <?php
    }

}

new PaymentPlan();