In ScheduleOnce, expand the left sidebar and navigate to Integrations > Zapier integration. Open the Manage Zaps tab and find the Zap. Click the pencil icon to open the Zap Editor and test the ScheduleOnce trigger.
If this does not solve the issue, you’ll need to regenerate your API key in ScheduleOnce. Open the left side bar and navigate to Integrations > Zapier integration > API Key tab. Regenerate the key and reconnect. Make sure you enter the new API Key in Zapier.
Read more in this troubleshooting article.
If you're using Booking with approval mode in ScheduleOnce, you'll need to approve the meetings in ScheduleOnce before the trigger is fired. Alternatively, you can switch to Automatic booking, which will automatically confirm the booking and trigger Zapier in one step. You can find more information about this booking mode in this article.
Booking Completed means that the time for the appointment has passed. You can either use another trigger in ScheduleOnce that matches your intention, e.g., Scheduled Booking, or set the appointment time to be in the near future and re-test.
Check out the Zapier integration articles in the ScheduleOnce knowledgebase.