How do I create a Cognito authorizer for the Amplify REST API?

I was using the Amplify React project and added an API Gateway (REST API).

I want to add a Cognito authorizer for that REST API.

Its default JSON is

{
  "version": 1,
  "paths": {
    "/notification": {
      "name": "/notification",
      "lambdaFunction": "WebhookNotification",
      "permissions": {
        "groups": {
          "Admin": [
            "create",
            "read",
            "update",
            "delete"
          ],
          "Customers": [
            "create",
            "read",
            "update",
            "delete"
          ]
        },
        "setting": "private"
      }
    }
  }
}