show-my-ip

This add-on allows you to view your IP address from your browser without having to navigate to sites like https://www.whatismyip.com/

Furthermore, as this add-on is open source, you don't need to be worried about your privacy.

You can look at the source code at the following address: https://github.com/TwinProduction/show-my-ip

This add-on does not save any of your information, however, since it's not possible to directly access your public IP address without a 3rd party server, it does require access to the following URL:
https://twin.sh/api/v1/ip

In case that API goes down, a call will be made to the fallback API:
http://ip-api.com/line?fields=query