How does the settlement page of woocommerce load other headers?

I want the woocommerce checkout page to load a separate header. Why can"t I find the relevant php template page that I can modify? I looked at figure 2, which was loaded into the wp page as a short code. What should I do if I want to load independent headers?

Mar.10,2021

if you select a template file on the right when you create a new page, you can add a new xxx.php file to the theme file home and add the corresponding template name to the header

.
<?php 
/* 
Template Name: 
*/ 
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b2b88f-2baab.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b2b88f-2baab.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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