curl --request POST \
  --url https://console.vast.ai/api/v0/users/ \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "email": "user@example.com",
  "username": "testuser123",
  "password": "securepass123",
  "host_only": true,
  "parent_id": "me",
  "ssh_key": "<string>",
  "captcha": "<string>"
}'

{
  "id": 12345,
  "username": "testuser",
  "email": "user@example.com",
  "key_id": 67890
}