Add a POST request to this endpoint. This should not specify an ID (one will be auto-generated sever-side), and should include a JSON body of the defined blog post. The endpoint should respond with the auto-generated post ID. This endpoint should require a "write-posts" scope.
Here is an example of how you can add a POST request to the endpoint:
```
POST /blog/posts HTTP/1.1
Content-Type: application/json
Authorization: Bearer YOUR_ACCESS_TOKEN

{
  "title": "New Blog Post",
  "content": "This is the content of the new blog post",
  "author": "John Doe",
  "published_at": "2023-02-20T14:30:00Z"
}
```
In this example, the request body contains a JSON object with the properties `title`, `content`, `author`, and `published_at`, which define the new blog post.

The response from the server should include the auto-generated post ID:
```
HTTP/1.1 201 Created
Content-Type: application/json

{
  "id": 42
}
```
In this example, the response includes a JSON object with a single property `id`, which contains the auto-generated ID of the new blog post.

To require the "write-posts" scope, you can add an authentication mechanism to your API that checks the scope of the access token sent in the `Authorization` header. For example, using OAuth 2.0, you can specify the required scope in the token endpoint:
```
https://your-api.com/token?grant_type=client_credentials&scope=write-posts
```
Then, in your API, you can check the scope of the access token sent in the `Authorization
POST /posts 
Content-Type: application/json 
{
  "blogPost": {
    "title": "My Blog Post",
    "body": "This is my blog post."
  }
}