curl --request PUT \
  --url https://api.ctrl-hub.com/v3/training-items/{training_item_id} \
  --header 'Content-Type: application/vnd.api+json' \
  --header 'X-Session-Token: <api-key>' \
  --data '
{
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "type": "<string>",
    "attributes": {
      "name": "<string>",
      "timing": "prior_to_starting_work",
      "description": "<string>"
    }
  }
}
'

{
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "type": "<string>",
    "attributes": {
      "name": "<string>",
      "timing": "prior_to_starting_work",
      "description": "<string>"
    },
    "relationships": {
      "organisation": {
        "data": {
          "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
          "type": "<string>"
        }
      }
    }
  },
  "jsonapi": {
    "version": "<string>"
  }
}