1. Find /wp-admin/themes/myhome/header.php

2. Backup file

3. Edit file

4. Find

<?php if ( My_Home_Theme()->layout->has_header_phone() ) : ?>
<span class="mh-top-header__element mh-top-header__element--phone">
<a href="tel:<?php echo esc_html( My_Home_Theme()->layout->get_header_phone_href() ); ?>">
<i class="flaticon-phone"></i>
<?php echo esc_html( My_Home_Theme()->layout->get_header_phone() ); ?>
</a>
</span>
<?php endif; ?>

5. Change to

<span class="mh-top-header__element mh-top-header__element--phone">
<a href="tel:01234567890">
<i class="flaticon-phone"></i>
0123-456-7890
</a>
/
<a href="tel:0321-654-9876">
0321-654-9876
</a>
</span>

6. It will look like this:

7..