How to create Ceph S3 in Proxmox GUI?

Not that I know of and I don't see the point in doing so because it has nothing to do with virtualization. Maybe stick to the CEPH documentation, which will show you how to do this.
 
Not that I know of and I don't see the point in doing so because it has nothing to do with virtualization. Maybe stick to the CEPH documentation, which will show you how to do this.
I was thinking it can provide S3 for VMs.