The terminal will provide a link. Follow that link on your mobile browser. Enter your PUBLIC IP address.
With so many ISP assign dynamic IP address to their customer, it doesn't seem to be practical. Entering new IP address when you reboot the modem or ISP assign new IP address after some time is rather cumbersome.
I’m working on self hosting options, but I may be able to remove the need to type in your IP address. You can also delete all the localtunnel code and use ngrok to tunnel the wallet, but ngrok is not open source. It has some nice features though.
Eventually, the plan is to have an executable that you just open and immediately have your url and wallet without friction.