If you would like to display only “Booking with Payment” option in final checkout page then you have to add below given code in your child theme functions.php file.

Please refer to below-given link to know how to create the child theme.

http://wptravel.io/how-to-create-a-child-theme/

After creating the child theme add below given custom code in your child theme functions.php file.

function wp_travel_customize_booking_option($fields){

$fields['payment_fields']['booking_option'] = array(
'type' => 'select',
'label' => 'Booking Options',
'name' => 'wp_travel_booking_option',
'id' => 'wp-travel-option',
'validations' => array(
'required' => 1
),

'options' => array('booking_with_payment' => 'Booking with payment' ),
'default' => 'booking_with_payment',

'priority' => 100

);

return $fields;
}
add_filter( 'wp_travel_checkout_fields', 'wp_travel_customize_booking_option' );