Hello @HaiNN You should have a profile available in Klaviyo to associate an event.

Thank you for answer my question, can you explain more for me about it? The flow im using is, i create custom metric then i create segment with trigger is this custom metric. When customer do something in store (example: customer register) i call API create event (https://developers.klaviyo.com/en/reference/create_event) with this custom metric and profile of this customer, it will create a profile in Klaviyo. Is this profile will show in app?

Thank you.

@HaiNN,The profile should show up in the UI. These events are created async so it may take some time before the event & profile show up in the UI.

A few things to check 
1. are you receiving a 202 response from the API? If not, the output should provide more details about the error 
2. are you using an email address that ends in “@example.com” or “@test.com”? These may be dropped by Klaviyo, since they’re not real email addresses. 
3. It’s possible you’re using a profile ID and a conflicting identifier, as discussed in this post: 

 
We need a few more details on what you’re currently doing and the behavior you’re seeing in order to help here.