[evfanknitram]

> Then, how do you recover?

In case this is not a rethorical question: Using the backup codes or a copy of the barcode you printed.

Regardless of what method you use I assume you want a secure backup method.

> but you can get a new sim

Maybe easily if you are a private person and happen to lose the phone in your home country during opening hours. I tried this method once but the company just forwarded me to the internal helpdesk of the company I work for (this is a good thing, but previously they issued SIM cards to me). Got a sim like a week later.