curl --request POST \
  --url https://api.example.com/v1/onboarding/session-token/generate \
  --header 'Content-Type: application/json' \
  --header 'x-ws-api-key: <api-key>' \
  --data '
{
  "userId": "user_123456789"
}
'

{
  "sessionToken": "session_token_abc123"
}