curl --request POST \
  --url https://realtime-api.voiceflow.com/v1/stable/function-variable \
  --header 'Authorization: Bearer <token>'
  --header 'Content-Type: application/json' \
  --data '{
  "name": "<string>",
  "type": "input",
  "functionID": "<string>",
  "description": "<string>"
}'

const response = await fetch('https://realtime-api.voiceflow.com/v1/stable/function-variable?projectID=<projectID>&environmentAlias=<environmentAlias>', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer <token>',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "name": "<string>",
    "type": "input",
    "functionID": "<string>",
    "description": "<string>"
  }),
});
const data = await response.json();

import requests

response = requests.post(
    'https://realtime-api.voiceflow.com/v1/stable/function-variable?projectID=<projectID>&environmentAlias=<environmentAlias>',
    headers={'Authorization': 'Bearer <token>'},
    json={
      "name": "<string>",
      "type": "input",
      "functionID": "<string>",
      "description": "<string>"
    },
)
data = response.json()

vf function variable create --project-id <projectID> --environment-alias <environmentAlias> \
  < body.json