> For the complete documentation index, see [llms.txt](https://docs.firework.com/firework-for-developers/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.firework.com/firework-for-developers/web/integration-guide/video-customization/cta-button-configuration.md).

# CTA Button

You can change CTA label and URL on the fly. You need to ensure that there is a CTA already added to the video for the change to reflect.

Firework allows you to modify video properties within any video related custom event. For the list of events see "[Video Events](/firework-for-developers/web/integration-guide/events/video-player-events.md)"

Example:

```javascript
     document.addEventListener('fw:video:impression', function (event) {
        event.detail.actions.video.update(({ videoFactory }) =>
          videoFactory((v) =>
            v
              .actionType('Watch now!')
              .actionUrl('https://www.youtube.com/watch?v=dQw4w9WgXcQ')
          )
        )
      })
```