How do I look up an Instagram profile by handle or user id?

Use GET /v1/instagram/profiles/{handle} when you have a username (with or without the leading @) — it returns the full profile card and uses found / private / restricted / not_found on data.lookupStatus. Use GET /v1/instagram/profiles/{userId}/basic when you already store Instagram's numeric platformUserId and want a lighter card without a username round-trip.