curl --request PATCH \
  --url https://realtime-api.voiceflow.com/v1/stable/document/<documentID> \
  --header 'Authorization: Bearer <token>'
  --header 'Content-Type: application/json' \
  --data '{
  "metadata": [
    {
      "key": "<string>",
      "values": [
        "<string>"
      ]
    }
  ]
}'

const response = await fetch('https://realtime-api.voiceflow.com/v1/stable/document/<documentID>?projectID=<projectID>&environmentAlias=<environmentAlias>', {
  method: 'PATCH',
  headers: {
    Authorization: 'Bearer <token>',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "metadata": [
      {
        "key": "<string>",
        "values": [
          "<string>"
        ]
      }
    ]
  }),
});
const data = await response.json();

import requests

response = requests.patch(
    'https://realtime-api.voiceflow.com/v1/stable/document/<documentID>?projectID=<projectID>&environmentAlias=<environmentAlias>',
    headers={'Authorization': 'Bearer <token>'},
    json={
      "metadata": [
        {
          "key": "<string>",
          "values": [
            "<string>"
          ]
        }
      ]
    },
)
data = response.json()

vf document update --document-id <documentID> --project-id <projectID> --environment-alias <environmentAlias> \
  < body.json