I'm building a webhook for another web service to hit when certain events fire. I want to make sure its secure so that it cannot just be spammed. I cannot for the life of me find an example app where it has a webhook with some kind of clientid/clientSecret or bearer/token authorization in it. Everything I search for has to do with implementing Stripe, or using some special 3rd party service to do it.

Can anyone suggest to me an example or tutorial on how to implement a secure webhook endpoint within nextjs preferrably without some special 3rd party service?