guz

[ripe wind]

It means the session has expired, when happens after a predetermined period of time: https://stripe.com/docs/api/checkout/sessions/object#checkout_session_object-expires_at

So yes, they haven't paid

The costumer may have clicked cancel url?
Also when the user clicks the cancel url and after creates another checkout session, do these checkout session have different id?
cancel_url won't fire that event no. Yes, the new session will have a different, unique cs_xxx ID

[novel slate]

Is there any way I can know if the user clicks cancel url?

[ripe wind]

I guess you could add some tracking event in your cancel_url, like here: https://stripe.com/docs/payments/checkout/analyze-conversion-funnel#setup

[novel slate]

thank you very much