This very simple workflow loads the content of a URL at ipecho.net which contains just the external IP address of the iOS device you are using to run the workflow. This is not the IP address of your device on the local network, but rather the IP address of your connection (cellular or WiFi) out onto the Internet.
The workflow displays the IP address within an alert box with the offer to copy it to the device clipboard. If the user cancels the workflow ends at this point. If not, the contents of the device clipboard will be replaced with the IP address found on the web page.