You can delete an environment to recover storage space and to remove Personally Identifiable Information (PII).
You can't delete the default environment.
Sign in to https://admin.powerplatform.microsoft.com.
Select an environment and then select Delete.
Provide the confirmation data and then select Confirm.
The URL of a deleted environment can't be used again for another environment until at least 24 hours have passed since the environment deletion.
“After a URL name change is saved, all users who access that environment must be notified of the change. Users will be able to access the environment for up to 24 hours by using the previous URL. After the 24-hour period has passed, the previous URL will not work.”