I might be looking in the wrong area but I don’t see anything where Classy sends an event out to a registered application.
IIRC, the way the existing APIs work (such as streamlabs, twitch, etc) is when an event occurs (such as a donation, a follow, sub, bit donation, so on) they send out said event to all the registered applications using their own API. PhantomBot just receives the event and handles it accordingly.
If Classy doesn’t have something like that, then donation notifications won’t be instant, as you will have to set up some form of a timer to hit the API every so often and retrieve the data. From there you have to parse it into your database in order to prevent duplicate alerts.
Long story short, it is entirely possible. But it will require a custom script at the minimal.