Proxmox VE with LVM thin

Hi,
I am using OVH server and they got a template for me to easy create PVE 8.x server, but it use Soft RAID 1 and must have a partition mount on /var/lib/vz, pls check my screenshot.
I want to use LVM thin for /var/lib/vz 300GB, and the rest of space for VM storage.

How can I do that ?

Regards,

James