Change the slug of a particular page every x hours

You’ll need a two step process for that.

1. Create a function that actually changes the slug (not rewrite it)
2. Schedule an event in WordPress to run that function in every X hours.

Here are something to start with

function wpse402903_schedule_event() {

    add_action( 'wpse402903_cron', 'wpse402903_cron_callback' );
    
    if ( !wp_next_scheduled('wpse402903_cron') ) {
        //Change 12 to your interval
        wp_schedule_event( time(), 12 * HOUR_IN_SECONDS, 'wpse402903_cron' );
    }
}
add_action( 'init', 'wpse402903_schedule_event' );

function wpse402903_cron_callback() {
    
    $post_id = 123; //The ID of the Post
    
    $postID = wp_insert_post( array(
        'ID' => $post_id,
        'post_name' => 'your-new-slug', //always use sanitize_title() if this generates dynamically.
    ));
}  

The only drawback is the WP Cron. It acivates only if someone visits your site. For a site with regular traffic, this is not a problem though.