Google cloud endpoints API key is not verified

I'm now developing REST API with Cloud endpoints and App engine. I will like to implement api key authentication but it does not work.

Looks good without query params of 'key=${API KEY}'.

# curl -X POST https://hogehoge.com/test -d '{"key":"value"}'
{
 "code": 16,
 "message": "Method doesn't allow unregistered callers (callers without established identity). Please use API Key or other form of API consumer identity to call this API.",
 "details": [
  {
   "@type": "type.googleapis.com/google.rpc.DebugInfo",
   "stackEntries": [],
   "detail": "service_control"
  }
 ]
}

But any key can be granted to access to the backend.

# curl -X POST https://hogehoge.com/test?key=aaa -d '{"key":"value"}'
POST is sended.

Of course, API key generated via API management will work.

# curl -X POST https://hogehoge.com/test?key=${realkey} -d '{"key":"value"}'
POST is sended.

Cloud endpoint file definition is

swagger: "2.0"
info:
  title: "xxxxxxxxx"
  description: "xxxxxxxxx"
  version: "1.0.0"
host: "hogehoge.com"
schemes:
  - "https"
security: []
paths:
  "/test":
    post:
      description: "test"
      operationId: "test"
      security:
        - api_key: []
      parameters:
        - name: body
          in: body
          required: true
          schema:
            $ref: '#/definitions/testRequest'
      responses:
        201:
          description: "Success"
          schema:
            $ref: '#/definitions/testResponse'
definitions:
  testRequest:
    type: object
    required:
      - data
    properties:
      data:
        type: object
        required:
          - key
        properties:
          token:
            type: string
            example: value
            maxLength: 20
  testResponse:
    type: string

securityDefinitions:
  api_key:
    type: "apiKey"
    name: "key"
    in: "query"

What I expect is only key generated via API management will be granted to access. Let me know how to solve this issue.

Thanks.

It seems that the Service Control API might not be enabled on your project.

In order to check that, you can run

gcloud services list --enabled --project your-gcloud-project-name

If servicecontrol.googleapis.com is not listed in the result of the previous command, you should run

gcloud services enable servicecontrol.googleapis.com --project your-gcloud-project-name

Furthermore, you could check that you have all the required services for Endpoints enabled. You can see how to do this in the documentation