Event grid triggered Azure function return unexpected status code 400 local testing

Hi! I'm raising an issue because I am trying to test a PowerShell event grid triggered azure function locally by following the steps [here](https://learn.microsoft.com/en-us/azure/azure-functions/event-grid-how-tos?source=recommendations&tabs=v2%2Cportal#local-testing-with-viewer-web-app) but every time I post the copied event, I get a bad request response. Hoping someone can help with this,

Edit: just noticed that the readme doesn't account for event grid trigger as being available however there is documentation for its use [here](https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-event-grid-trigger?tabs=in-process%2Cextensionv3&pivots=programming-language-powershell). Just curious as to which is accurate


Thanks