curl --request POST \
  --url https://staging.api.commercengine.io/api/v1/{store_id}/storefront/auth/login/email \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "email": "jsmith@example.com",
  "register_if_not_exists": true
}'

{
  "message": "<string>",
  "success": true,
  "content": {
    "otp_token": "<string>",
    "otp_action": "<string>"
  }
}