# Events Events are fired by `Tebex.checkout` upon specific actions to alert your frontend and enable you to take action when required. These events should **not** be used to confirm actual receipt of payment - you should use [Webhooks](https://docs.tebex.io/developers/webhooks) instead. To add a checkout event callback, use `Tebex.checkout.on()` . The first argument to this function should be the name of the event to listen to, and the second argument should be a function to call when that event is fired: ```javascript Tebex.checkout.on("payment:complete", (event) => { console.log("Payment completed!", event); }); ``` Available events are as follows:
NameFired Upon
"open"The portal popup opening after calling Tebex.checkout.launch().
"close"The portal popup closing after being dismissed by the user.
"payment:complete"The customer has successfully completed their payment.
"payment:error"The customer experienced an error, such as incorrect card details or insufficient funds, when making a payment.
All events that can be listened to with [`Tebex.checkout.on()`](#events) are exposed on the element as custom DOM events, which means you can use addEventListener to subscribe to them: ```html ```