curl --request POST \
  --url https://api.rownd.io/hub/auth/magic \
  --header 'Content-Type: application/json' \
  --header 'x-rownd-app-key: <api-key>' \
  --header 'x-rownd-app-secret: <api-key>' \
  --data '{
  "purpose": "auth",
  "redirect_url": "/somewhere/in/my/app#",
  "expiration": "30d",
  "link_data": {},
  "verification_type": "email",
  "data": {
    "email": "gary@foo.com",
    "first_name": "Gary"
  },
  "user_id": "__default__",
  "group_to_join": "<string>"
}'

{
  "link": "https://rownd.link/c8fLG0a",
  "app_user_id": "user_fmpsrdqfcqzyicf3msor42e8"
}