When you no longer need your frontend, you can delete it either via the Dynatrace web UI or via API.
To delete a frontend via Dynatrace web UI
Experience Vitals > Overview.frontend.name of the frontend and select Delete to confirm.To delete a web or mobile frontend via API, send a DELETE /frontends/{id} request with the frontend ID. You need a platform token or OAuth access token with the rum:frontends:delete scope.