Turn your scenario off and then on again. It will prompt you to delete all the data in the queue, or process all the older requests first.
Then keep the scenario turned on, otherwise new requests will enter the webhook queue and not get processed.
Hope this helps! Let me know if there are any further questions or issues.
— @samliew
P.S.: Did you know, the concepts of about 70% of questions asked on this forum are already covered in the Make Academy. Investing some effort into it will save you lots of time and frustration using Make later!