In swagger post parameters on registration

Question

With api 3 version I want to make register enntry, with most common fields : name, email, password, password_confirmation I needs somewhow to describe POST parameters, looks like that is not parameters? I tried to make as :

  /register:
    post:
      tags:
        - user account
      summary: Register user
      operationId: postRegister
#      parameters:
      responses:
        '200':
          description: Successful registration
          content:
            application/json:
        '400':
          description: Invalid register data

1) How can I describe POST parameters ? 2) I checking http://petstore.swagger.io/ examples and I do not see any Register/login functionality. Are there some other examples Register/login functionality?

Thanks!