JetFormBuilder Update Field addon - custom callback

code.php

<?php

function jfb_tour_get_data( $field_name, $form_id, $form_fields ) {
	
	$args = array(
		'tour_id'          => $form_fields['tour_id'] ?? '',
		'number_of_guests' => $form_fields['number_of_guests'] ?? '',
		'date'             => $form_fields['date'] ?? '',
	);
	
	$url = add_query_arg( $args, 'some URL' );
	
	$response = wp_remote_get( $url );
	
	if ( 200 !== wp_remote_retrieve_response_code( $response ) ) {
		return '';
	}
	
	$json = wp_remote_retrieve_body( $response );
	
	if ( empty( $json ) ) {
		return array();
	}
	
	$data = json_decode( wp_specialchars_decode( stripcslashes( $json ), ENT_COMPAT ) );
	
	if ( empty( $data ) ) {
		return array();
	}
	
	return $data;
	
}

function jfb_tour_get_price( $field_name, $form_id, $form_fields ) {
	
	$data = jfb_tour_get_data( $field_name, $form_id, $form_fields );
	
	if ( empty( $data ) ) {
		return 0;
	}
	
	return $data->price ?? 0;
	
}