I use an external usb that I swap out every month to an off-site location.
I use pvesm to disable the backup storage, umount the drive, plug in the new one, enable again with pvesm. I have that drive as noauto,x-systemd.automount in /etc/fstab which causes it to get mounted automatically when the mount point is touched by pve. And it mounts by disk label so getting a different device name doesn't cause any issues.