Changing default email template for POS orders

functions.php

<?php 
// This would go in your theme fucntions.php file, or you could create a new plugin

/**
 * Change Email Subject and Heading
 */
function wc_custom_email_template_order_details( $order, $sent_to_admin, $plain_text, $email ) {
    // If POS order, change the template
    if ( $order->get_meta( '_pos' ) ) {
        // Example: Change the email heading
        $email->heading = 'Custom Email Heading';
      
      // Example: Change the email subject
        $email->subject = 'Custom Email Subject';
    }
}
add_action( 'woocommerce_email_order_details', 'wc_custom_email_template_order_details', 10, 4 );

/**
 * Change Before Order Table
 */
function wc_custom_email_template_before_order_table( $order, $sent_to_admin, $plain_text, $email ) {
    if ( $order->get_meta( '_pos' ) ) {
        echo '<p>Custom content before order table.</p>';
    }
}
add_action( 'woocommerce_email_before_order_table', 'wc_custom_email_template_before_order_table', 10, 4 );

/**
 * Change After Order Table
 */
function wc_custom_email_template_after_order_table( $order, $sent_to_admin, $plain_text, $email ) {
    if ( $order->get_meta( '_pos' ) ) {
        echo '<p>Custom content after order table.</p>';
    }
}
add_action( 'woocommerce_email_after_order_table', 'wc_custom_email_template_after_order_table', 10, 4 );

/**
 * Add Custom CSS Styles
 */
function wc_custom_email_template_styles( $css ) {
    $css .= "
        .custom-email-class {
            font-weight: bold;
            color: #f00;
        }
    ";
    return $css;
}
add_filter( 'woocommerce_email_styles', 'wc_custom_email_template_styles' );