Reference doc

https://docs.microsoft.com/en-us/cli/azure/keyvault?view=azure-cli-latest#az-keyvault-purge

deleting a key-vault

list all keyvaults of type vault (as opposed to hsm) in the subscription “my-test-subscription”

az keyvault list --resource-type vault  --subscription my-test-subscription

delete the keyvault (this will delete it but it’ll still be recoverable)

az keyvault delete  --name my-test-keyvault  --subscription my-test-subscription

purge (this will actually delete it and it will no longer be recoverable)

az keyvault purge  --name my-test-keyvault  --subscription my-test-subscription

make sure it’s not in a soft deleted / recoverable stage

az keyvault list-deleted --resource-type vault --subscription  my-test-subscription