booking-api.php

<?php

$consumer_key    = 'ck_b6dab226d72e3b3da3462f9b51bc672b886f8f85';
$consumer_secret = 'cs_912b18aeedb2883a9c53f877a3c77fc7c0082fc4';
$url = rest_url( 'wp/v2/bkap-bookings/16180/' );
$url             = add_query_arg(
  array(
    'consumer_key'    => $consumer_key,
    'consumer_secret' => $consumer_secret
  ),
  $url
);
$response        = wp_remote_get( $url, array( 'sslverify' => false ) );

// Check the response code.
if ( wp_remote_retrieve_response_code( $response ) != 200 || ( empty( wp_remote_retrieve_body( $response ) ) ) ) {
  // If not a 200, HTTP request failed.
  die( 'There was an error attempting to access the API.' );
}

$bookings = json_decode( wp_remote_retrieve_body( $response ) );