Sharing of information between back end and front end developers

This question is not related to code or any bug. I have an organisation related query. I am a front end developer. I consume web API's developed by the back end developers in my company. The problem here is, they share it via postman. API's are segregated project wise in folders. Problem is, the nomenclature of the API as well as the functionality differs. This creates lot of confusion for me while consuming API's. secondly, There is no indication that whether the API is deployed on a server or not. So sometimes, I end up writing the code and realize that the specific API is not deployed yet.

My question is, how does the world do it? How is the communication between developers established with this specific domain? How can one overcome this problem?