Hi @awylon,
Welcome to the Auth0 Community!
There isn’t an Action for user update like there is for post-login or password change.
You can essentially build your own Action on any log event (in this case you would want Success API Operation sapi) by using Log Streams and AWS EventBridge + Lambda Function.
You will send a stream of logs to EventBridge, set to trigger a lambda on the specific event you are looking for.
Does that make sense?