ads_setup.php

<?php
/**
 * Allows you to modify any part of the custom post type registration
 *
 * see: https://codex.wordpress.org/Function_Reference/register_post_type
 */
function example_ads_setup( $args = array() ) {

	// Change the permalink structure for the custom post type
	$args['rewrite'] = array(
		'slug' => 'go', // http://example.com/go/single-ad-slug
	);
	
	// Expose ads in the REST API
	$args['show_in_rest'] = true;
	
	return $args;
	
}

add_filter( 'ads_setup', 'example_ads_setup' );