How to change the size of the system disk when deploying a VM from a template?

Question

KVM

Salute comrades!
Please share your success stories on how to resize the system disk when deploying a VM from a template. In the template, the system disk has a size of 20Gb, and at the moment I see only an option with adding another disk, a larger one, and stretching LVM onto it.
To be honest, I do not have much experience in working with clouds, and so far I have not found information on how this is done by various providers.
Thank you for your help