Customizing embedded checkout with events

[techdaddies-kevin]

I know that we can customize the embedded checkout slightly with onLoad and onComplete events docs but I'm having a terrible time trying to figure out how to actually set up the event syntactically.

Basically, we're using the BigCommerce Wordpress plugin with embedded checkout. The plugin passes the configuration of the checkout via a data-js property, and we can customize that. I have tried various configurations of passing JSON objects into this, but no matter what I do, I cannot get my custom JS to execute. I cannot figure out what syntax the SDK is looking for.

Any help would be appreciated. If I can just see an example of the JSON that the SDK needs to fire an onLoad event, I can take that and implement it into the WP plugin. But that syntax is the spot we're stuck on currently.