So I've been reading GitHub developer docs and about webhooks they have the following statement:
Webhooks allow you to build or set up GitHub Apps which subscribe to certain events on GitHub.com. When one of those events is triggered, we'll send a HTTP POST payload to the webhook's configured URL. Webhooks can be used to update an external issue tracker, trigger CI builds, update a backup mirror, or even deploy to your production server. You're only limited by your imagination.
However, about Apps they've also got this statement:
Apps on GitHub extend and improve existing workflows. People can purchase apps from GitHub Marketplace or browse useful tools and services that integrate with GitHub in Works with GitHub.
If you're building or adding integrations, this documentation will help get you up and running.
For support requests, bug reports, and discussions related to GitHub Apps (not OAuth Apps), use the GitHub Platform Forum. The forum allows you to collaborate with other integrators as well as engineers and product managers from GitHub.
If your request is about OAuth Apps, or if you need to discuss a private concern, please contact support directly.
This seems that Webhooks can only be used with GitHub Apps? The difference between GitHub Apps and GitHub OAuth Apps isn't very clear and I fail to see why an OAuth app would not be able to use Webhooks?