Pin IDs can be found by looking at a Pin’s URL. The string of numbers at the end of the URL is the Pin ID (example: pinterest.com/pin/617415430169271912).
The 12-digit number beginning with 687 under the Ad name is the ad ID.
If you want to find the ID of an ad that is pending, or has been paused or rejected:
Click Status at the top of the page and scroll to Ad status
Click the box beside “Approved” so that only “Pending”, “Paused” and “Rejected” are selected
The Pin ID is the 18-digit number at the top of the page at the end of the URL.