How to Keep VMs for a Longer Period?

To preserve the service’s VM, make the following steps:

Turn off the machine. The active CPU and Mem resources are not consumed and only storage is used (it will be used anyway).
Disable the periodic backups function.
(optionally) Ask the technical support service to move the machine to a slow disk to save the storage cost.

You can also make a special mark “Archive machine” in the UI so that it does not appear by default in the list of services.