Creating a fork with the GitHub V3 API (REST)

I'm trying to fork a repo using the GitHub V3 API via REST, however, I am having issues making a POST request as per the docs (https://developer.github.com/v3/repos/forks/#create-a-fork).

Basically, what I have so far:

A logged-in user with an OAuth Token
A POST request setup to the API (URL: https://api.github.com/repos/carmichaelalonso/infiniteflight/forks/) - I am testing this with hurl.it to begin with.
Headers in the request: one has the name Authorization with the value 'token ...', the other specifies Content-Type with the value application/json
A body with the following JSON: {"organization" : "shortlisthome"} (shortlisthome is the account I am trying to fork the repo to.

I am not intending to fork this to an organization, instead of a standard user account, which is where I am getting confused. When I run the request, I do not get any authentication errors or 404 errors (I previously had but I had been entering incorrect values by mistake, causing such errors).

When I run this request though, I get the following result (a 422 unprocessable request):

{
    "message": "Validation Failed",
    "documentation_url": "---url-to-docs---",
    "errors": [
        {
            "resource": "Fork",
            "code": "invalid",
            "field": "organization"
        }
    ]
}

I am unsure whether or not I am able to fork this to a standard user, or if it is an error with my request. Please let me know if I can provide any more info (first post here so a bit unfamiliar with the convention).

Solution

In order for shortlisthome to fork the repository you need to authenticate as them. The repository you're trying to fork is public, so all you need to do is obtain a OAuth token for shortlisthome and then make a similar request to the one you're making now. The only difference will be that you do not need to provide the JSON body of {"organization": "shortlisthome"}.

For what it is worth, the optional JSON body is intended for you to use when you are a member of an organization with proper permissions and you want to fork the repository to that organization. You cannot fork a repository to someone else's account unless you are authenticated as them.