Vxrail Vsan Storage Policy

Hi,

I have 4 Hosts  Vxrail 670Feach one with 2 cache disk NVME 1.6TB  +8 Disks SSD 3.84 TB , i can't able to Create VSAN storage policy Raid  RAID 5

Error During select  create new Storage Poilcy  when selectRaid5/6 Erasure Code ( Error No Flash exist and can't Continue)

1-VSAN License Advanced , Vsphere Licenses is standard both activated and assigned

2-VXRAil Manager is 7.0.370