1. Module - the Klaviyo card must be enabled for your account; without it nothing is sent even if keys are saved.
2. Keys - both the Public Key and Private Key must be present on the Klaviyo card. If either is wrong (including a private key without the right access scopes), Sprwt's calls to Klaviyo just fail quietly in the background - there's no on-screen error - so double-check they were copied correctly from Klaviyo's API Keys page.
3. Email address - events are attached to the customer's email; customers without a valid email (for example POS walk-ins) are skipped, and orders fall back to the checkout's billing email when there's no linked customer account.
4. Metrics - Klaviyo only shows a metric (and lets you build a flow off it) after Sprwt actually sends that event type at least once; there is no manual "sync" button in the current version, so a metric for an event type that has never fired won't exist yet in Klaviyo.
5. Timing - order events are sent when the order is created, other events when the action occurs; Klaviyo may take a minute to display them.

Errors returned by Klaviyo are not surfaced on the Integrations page in the current version, so if the above are correct contact Sprwt support with an example customer email and time.