Is it possible to find out the address at which the webhook listens?

Question

Information Security

I thought about the security of the project and the following questions arose:

1. At a certain address, I expect a callback. Is it possible to find out this address somehow if it does not appear anywhere?
   
2. Is there any way to intercept the webhook I'm waiting for?
   

Answer 1

Yes, you somehow indicate the address of the callback to the third-party service. And no one canceled the scanning of addresses.
Nobody canceled MITM either.
Solution - use https and tokens