Log in to the rails app using Devise and token_authenticatable: "401 unauthorized"

I am trying to create an API to enter my rails application using Devise and authenticatable_token. I created a SessionController in my API module and wrote the following code for sign_in:

module Api
  module V1
    class SessionsController < Devise::SessionsController

      def create  
        resource = warden.authenticate!(scope: resource_name, recall: "#{controller_path}#new")
        sign_in(resource_name, resource) 
        if current_user  
          if !current_user.authentication_token  
            current_user.reset_authentication_token! 
          end
          render json: {success: true, auth_token: resource.authentication_token, email: resource.email}
        else 
          invalid_login_attempt
        end 
      end

      protected

      def invalid_login_attempt
        warden.custom_failure!
        render json: {success: false, message: "Error with your login or password"}, status: 401
      end
    end
  end
end

The problem is that the application calls 401 when I use the login without any tokens.

RestClient.post "http://localhost:3000/api/v1/users/sign_in", {user: {email: "tester@test.biz", password: "FILTERED"}}.to_json, :content_type => :json, :accept => :json

But if I installed the token that was provided by the registration method, it works:

response_json = RestClient.post "http://localhost:3000/api/v1/users/sign_in?auth_token=#{@token}", {user: {email: "tester@test.biz", password: "FILTERED"}}.to_json, :content_type => :json, :accept => :json

So why is that? Is it possible to disable the authentication process of a token when performing a character?