Thanks, you’re set to use the WP cron to run the messages. Please switch to Webhook method, save the settings, and run the webhook URL on a separate browser window/tab. Let me know if you get any errors.
Also make sure you still have your cron system running correctly, as sometimes people disable the WP Cron to turn on real cron jobs, but if something goes wrong with the real cron job, then WP Cron will never get called.
