By default reminders Queue gets checked every time anyone visits the site but if you have a hourly reminders it’s better to set up a Cron job

To setup a cron job you need to create an hourly cron job that will trigger this url on your site: YOURSITE.COM/wp-admin/admin-post.php?action=latepoint_route_call&route_name=reminders__process_reminders

You can use any of the free cron services available online, one of them is