Allow multiple cart items. Default is false.

Source

File: /core/helpers/cart.php
Used by: /core/helpers/cart.php, /core/REST/cart.php, /inc/booking-functions.php. /inc/class-ajax.php, /inc/payments/wp-travel-payments.php

Example:

function prefix_wp_travel_allow_multiple_cart_items() {
    return true;
    }
add_filter( 'wp_travel_allow_multiple_cart_items', 'prefix_wp_travel_allow_multiple_cart_items' );