If a campaign is not generating any impressions, the first step is always to check the campaign’s status in the Campaigns overview. A campaign only delivers content when its status is “Active”; statuses such as Draft, Scheduled, Paused, Completed or Archived will systematically prevent any content from being displayed, even if the campaign’s configuration appears to be otherwise entirely correct.
Also check whether the start and end dates of the campaign actually cover the current date, and whether the campaign has been accidentally paused manually – which, incidentally, is explicitly indicated in the Shirley’s Insights dashboard under “General” if this is the case.
If the status and schedule are correct, check the underlying links: is the linked element correctly configured and active, is the position where the element is supposed to appear itself active, and has the embed script for that position been effectively and correctly implemented on the website? For paid campaigns, it is also important to note that a campaign with a set total budget remains in “Draft” status until the payment has been processed, meaning it can only start effectively once payment has been successfully completed.
Finally, it is useful to check whether any display rules linked to the element are unintentionally excluding the pages on which you expect the campaign to appear.