Thanks! This is helpful.
The URL I'm using is https://198.168.100.2:8006/
This is the URL that appears in the Proxmox console.
I didn't enter a specific IP when installing Proxmox; I just left the default IP: 198.168.100.2
These are the results from ip a:
1: lo: <LOOPBACK, UP, LOWER_UP> mtu...