customize the booking price based on the custom fields

functions.php

<?php
function custom_price_calc( $price_data, $product_id ) {

	/*
	You can change the following data 
	total_price_calculated - Total Booking Price
	bkap_price_charged - Booking price being charged to customer [This could be vary if deposits addon is being used]
	bkap_price : Text being displayed in the Price section - https://prnt.sc/ku_AQFhjUY36
	To understand bit more how the data being prepared and passed based on the cutomer selection then you can check for bkap_special_booking_show_multiple_updated_price function
	*/
	echo '<pre>';
	print_r( $price_data ); // this variable contains the above shared details.
	print_r( $product_id ); // this variable contains the product id.
	print_r( $_POST ); // this variable contains all the selection made by the customer.
	echo '</pre>';

	/* Here you can fetch the price based on the selecte number of days from your custom field
	   and set to $price_data array
	*/

	return $price_data;

}
add_action( 'bkap_final_price_json_data', 'custom_price_calc', 10, 2 );