In general for Hot spare disks(drives) it is recommended to check your hardware manual, or contact the RAID Controller support team to find out there way of creating the Hot spare.

As you can use the hot spare drives to replace the damaged ( failed) drives in your RAID Array storage.

As when the drive get failed in your RAID Array, the RAID controller will start to look into all the disks (drives) that this controller controlling for a hot spare drive, and if there is an available disk(drive), then the RAID controller will replace the role of the damaged disk in the RAID Array with the hot spare disk.
And the data and parity bit are rebuilt from the other disks automatically ( This process is controlled by the RAID Controller ), and the RAID array is changed back to optimized state when the rebuild is complete.

The hot spare drives are useful only if the capacity of the drive is equal or greater than the capacity drive in an array that become degraded (damaged).

And in general, choose the more safer way to deal with disks.