restore physical host, not VM

Hi,
one of my backups is a physical server in debian on PBS, everything works but I wonder how to restore a backup if my physical server crashes

is there any procedure for this ?
-do I have to reinstall an OS then restore the bakcup files?
-do I have to load a backup client on a usb key?
-do you have an example or experience?

Please,what can i do with this 3 folders/ files on PBS :
catalog.pcat.didx
index.json.blob
user.pxar.didx

thanks in advance