Rather than printing money to pay off debts (as in a bail-out), those debts are simply cancelled.
Discussion
Wait what? I had an understanding that bail ins are when the bank confiscated accounts thah exceed 250k to pay off their debts
This article seems to agree with my understanding:
https://www.investopedia.com/terms/b/bailin.asp
Though I'm not certain that there aren't "bail-ins" that conform to your understanding too
Its there though, the cyprus expirement