Researching the internet I have found two great tools that can be used for testing webapps and webhooks.
The first is called ngrok. What it does is that it creates a tunel to your web app and makes it accessible from the internet through https without port forwarding. It acts as a kind of reverse vpn but for https access only. Its link is the following:
ngrok.com
The second and also very interesting tool is beeceptor. It is a webhook receiver and post api receiver in order to check what various services will post to your webapp and create the receiving code correctly. Its link is the following:
beeceptor.com
They are free to try.
The first is called ngrok. What it does is that it creates a tunel to your web app and makes it accessible from the internet through https without port forwarding. It acts as a kind of reverse vpn but for https access only. Its link is the following:

ngrok | API Gateway, Kubernetes Networking + Secure Tunnels
ngrok simplifies app delivery by unifying API gateway, Kubernetes Ingress, global load balancing, DDoS protection and more with secure tunnels.
The second and also very interesting tool is beeceptor. It is a webhook receiver and post api receiver in order to check what various services will post to your webapp and create the receiving code correctly. Its link is the following:

Beeceptor - Rest/SOAP API Mocking, HTTP Debugger & Proxy
Deploy a mock API server instantly. Build mock REST API and SOAP APIs without any coding. Inspect request and responses, HTTP debugging, intercepting and proxying. Best alternative to JSONplaceholder & Wiremock.

They are free to try.