How is the authentication token obtained?

Authentication tokens are usually obtained through a user login process. The client sends a request with credentials (such as username and password) to the authentication server. If the data is correct, the server returns a token — a unique string that confirms the user has been successfully authenticated.

Protocols like OAuth2 or JWT (JSON Web Token) are often used. An example request to obtain a token via REST API:

POST /auth/login HTTP/1.1
Content-Type: application/json

{
  "username": "user",
  "password": "pass"
}

The server responds with a token:

{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6..."
}

This token is then included in the headers of subsequent requests to access protected resources.