Wordpress Adding Custom Post Type on WP REST API

functions.php

<?php

/**
 * Add WCC contest details into the WP Rest API
 *
 * @param [class] $object Query Object.
 * @return string Contest details.
 */
function get_wcc_contest_details( $object ) {
    $wcc_contest_details = get_post_meta( $object['id'], '_wcc_contest_details', true );
    return rest_ensure_response( $wcc_contest_details );
}

/**
 * Register custom rest api fields
 *
 * @return void
 */
function mxc_wcc_contest_details() {

    register_rest_field( 'wcc_contest', 'wcc_contest_price', array(
        'get_callback' => 'get_wcc_contest_price',
        'schema'       => array(
            'description' => __( 'Contest Price' ),
            'type'        => 'text',
        ),
    ) );

}
add_action( 'rest_api_init', 'mxc_wcc_contest_details' );