I've been using Indicator System Monitor for years on Ubuntu 16.04:

I haven't used it with Gnome but the link above states:
Indicator-SysMonitor - v0.8.2
An Application Indicator showing cpu temperature, memory, network
speed, cpu usage, public IP address and internet connection status .
Works with Unity, Xubuntu, Gnome-Shell + app-indicator extension
together with any other desktop environments that support
AppIndicators.
Also works with the Budgie-Desktop
Offers the possibility to run your own command and display its output.
Even though it already offers an option to display Public IP you can still write your own bash script which refreshes every x seconds with custom display information, in my case above a spinning pizza with time remaining in washing machine wash cycle (so you are told when to add fabric softener for rinse cycle).
Indicator System Monitor is maintained by FossFreedom who is a regular visitor to Ask Ubuntu website.
bash
, I recommendcurl ifconfig.co
. I don't know how that will go to your GNOME panel, though. – Mukesh Sai Kumar Dec 23 '19 at 10:47