Where can I find good introductory literature and articles on network protocol verification?

Question

Communication protocols

Our team is developing a backend on a microservice architecture. Microservices communicate with each other using messages - in fact, this is its own application layer protocol.
Over time, this protocol became more complicated, and I wanted to have some way to formally describe and verify it.

I remember that at the institute they told me that Petri nets could be used for these purposes.

Please tell me some good introductory literature or articles on Petri nets and in general on methods of protocol verification.