Scheduling Poll is integrated with Skype for Business or Microsoft Teams. If your tenant admin has set your default online meeting provider, you'll see which provider they've selected when creating a new meeting and adding a Scheduling Poll. With Skype for Business or Microsoft Teams, you can use automatic or manual scheduling.
If you're using a third-party online meeting provider such as Zoom or Webex through an Outlook add-in, you can still schedule a meeting through Scheduling Poll, but you cannot use the auto schedule option.
Uncheck the Teams or Skype for Business checkbox and turn off auto schedule before you send your poll.
Once your poll has been sent and a sufficient number of attendees have voted on their preferred time, access your voting page to see the results.
Click Schedule meeting for the appropriate time slot, a new window with the meeting invite details will open, add your online meeting link through your Outlook add-in, and send the invite.