Node js communication with Chirpstak

ChirpStack (v4)
1

Does anyone have an example of how to make a POST, or full REST API in node js for the chirpstak API to create a gateway, or sensor node?

2

Have you looked at the API section of the docs?

https://www.chirpstack.io/docs/chirpstack/api/index.html

There is an example for the gRPC API using JavaScript, as well as pointers to the REST gateway, which includes full Swagger UI docs.