REST API: Problems with POST Dev resources

Hey, I’m trying to figure out how to create a dev resource with the REST API. The POST Endpoint should do this job, but it doesn't work for me.
No matter which node_id I specify, the same error always comes back:
 

{
  "links_created": [],
  "errors": [
    {
      "file_key": "***",
      "node_id": "794-1987",
      "error": "Invalid node_id"
    }
  ]
}