Update 1:
It looks like there is some issue/different setting for Azure Function.
I tested this functionality with https://webhook.site/052116bc-bfb8-437f-aca4-d08344bb642e webhook and can see result appearing on dashboard ( https://webhook.site/#!/052116bc-bfb8-437f-aca4-d08344bb642e/9bc8f813-eb65-4188-94f7-e65d2d5f625b/1)
Kind Regards
Hemant