Fire in WP Travel admin email settings tab. Fire before payment email template options.

Source

File: /inc/admin/views/tabs/tabs-contents/settings/email.php
Used by: /inc/admin/views/tabs/tabs-contents/settings/email.php

Parameter
$booking_client_email_settings

Example:

function prefix_wp_travel_multiple_booking_client_template( $booking_client_email_settings ) {
    esc_html_e( ‘This is content added using this hook’, ‘text-domain’ );
}
add_action( 'wp_travel_multiple_booking_client_template', 'prefix_wp_travel_multiple_booking_client_template’ );