[BUG][cpp-restsdk]How to define login API to return cookie from response header for cpp-restsdk generator

Description

I want to write a API for login request.
If the login request is successful then it API should return the cookie from the response header.

openapi-generator version 5.0.1

OpenAPI declaration file content or url

/api/v1/user/login:
    post:
      tags:
        - login/logout
      summary: Login as a user.
      description: Send login request
      operationId: loginUser
      requestBody:
        description: Send login credentials.
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              properties:               
                username:
                  type: string
                password:
                  type: string                
              required:               
                - username
                - password
              example:                
                username: usr
                password: '123'
      responses:
        '200':
          description: returns cookie from header.          
          content:
            text/html:
              schema:
                type: string
tags:
  - name: login/logout
    description: 'login, logout operations'

Generated Code:
The generated API function, it only returns the HTTP body instead of the extracting cookie from the header:
return localVarResponse.extract_string();
So, How can we get the cookie.

Generation Details

npx openapi-generator-cli generate -g cpp-restsdk -i test.yaml -o ./cpp

Steps to reproduce

Related issues/PRs

Suggest a fix

Start with test.yaml and run the reported npx openapi-generator-cli command for the cpp-restsdk generator. Inspect the generated loginUser API function, especially the return localVarResponse.extract_string() call, to determine how response headers are exposed. Done means reproducing the behavior and establishing a documented or testable way to obtain the login cookie.