How to use pos.transaction-complete.event.observe and when will it be released

Retail & Point of Sale
1

https://shopify.dev/docs/api/pos-ui-extensions/2025-04/targets/post-purchase/pos-transaction-complete-event-observe

I am interested in using this functionality in the near future. Is there any sample code that I can follow since I am not sure how it is implemented? Also, is there a timeline to when it will be in a stable release?