Hey there @Mitchell Zezima!
Ah, it looks like a similar question has been asked about before in the Community:
There isn’t a “New Credit Note” trigger for Xero at present. But as mentioned on that other topic, there is a feature request to have such a trigger added to the Xero integration. I’ve added your vote to that feature request. I don’t have any ETA on when that trigger would be added but you’ll get an email from us the minute it is!
Since this is already being discussed in the other topic I’m going to close out this post now so that we can keep track of any interest folks in one place. For anyone who comes across this and wants to have their vote added, please reach out on the main topic for this feature request directly. I’d also recommend subscribing to that topic to be kept informed of any news or workarounds shared there!