Why don’t you change a test secret and then manually check the contents of cloudtrail in the web console to see if anything is recorded. I would be surprised if there’s not, I’m sure this is an event that people would want to be able to track/identify
It looks to be the PutSecretValue event. Those docs say AWS CloudTrail records all API calls for Secrets Manager as events, including calls from the Secrets Manager console. CloudTrail also captures the following events, so the list on that page is not the only events it records, just the additional events