add_action('salesking_my_orders_custom_columns', function(){
?>
<th class="nk-tb-col tb-col-sm"><span class="sub-text"><?php esc_html_e('Payment Link','salesking'); ?></span></th>
<?php
});
add_action('salesking_my_orders_custom_columns_footer', function(){
?>
<th class="nk-tb-col tb-col-sm"><span class="sub-text"><?php esc_html_e('link','salesking'); ?></span></th>
<?php
});
add_action('salesking_my_orders_custom_columns_content', function($order){
?>
<td class="nk-tb-col tb-col-sm">
<div>
<span class="tb-sub">
<?php
echo '<a href="'.$order->get_checkout_payment_url().'">Payment URL</a>';
?>
</span>
</div>
</td>
<?php
}, 10, 1);