WooCommerce Hook after label purchase?

Hi, thanks for this great plugin.

I’d like to know, if there are any hooks (e.g. WooCommerce hooks), after a shipping label is purchased.

The reason I’m asking is, that I want to notify a Slack channel, after a label was purchased on the WooCommerce order page.

If you have a documentation for the plugin, that would also be helpful.

Thanks in advance for your answer.

Daniel