The Audits dashboard cannot be used until you have enabled the Cost Events Audit API via Helm. See the Cost Events Audit API doc for instructions.
The Audit dashboard provides a log of changes made to your deployment. It's powered by the Cost Events Audit API and the Predict API. Supported event types include creations and deletions of Deployments and StatefulSets.
Cost impact from additions or deletions is provided using the Predict API. Deletions should naturally result in cost savings, indicated by a negative value, with the opposite effect for additions.