Allow CORS on WP-API

allow-rest-api-cors.php

add_action( 'rest_api_init', 'handle_preflight' );

function handle_preflight() {
    header("Access-Control-Allow-Origin: *"); //Pay attention
    header("Access-Control-Allow-Methods: POST, GET, OPTIONS, PUT, DELETE");
    header("Access-Control-Allow-Credentials: true");
		header("Access-Control-Allow-Headers: x-requested-with,x-wp-nonce");

    if ( 'OPTIONS' == $_SERVER['REQUEST_METHOD'] ) {
        status_header(200);
        exit();
    }

}