I'm afraid I can't help with the TID and LUN; I used the exact text that appears in this thread and it worked for me.
As to the IP address, I believe this should be the CIDR of the network that should have access to the iSCSI device. So for example, if your DHCP server hands out `192.168.42.x`...
Just bumping this thread to report success with the instructions found above (post #4 by @maxprox on 2018-10-08).
To be clear about how things are connected and being used in this scenario:
I'm currently running Proxmox 7.1 (Linux 5.13.19-2-pve #1 SMP PVE 5.13.19-4 (Mon, 29 Nov 2021 12:10:09...