Generates a signed URL for reading/downloading an uploaded file. Private files get 30-minute URLs, public files get 24-hour URLs. Use the ttl query param to request a shorter TTL (capped at the max for the visibility level).
Authentication via JWT token or API key. JWT: Get from Veryfront dashboard. API Key: Format "vf_
Project ID or slug
Upload ID (UUID) or URL-encoded file path
Requested TTL in seconds (min 60, capped at max for visibility level)
60 <= x <= 86400