Just what's mentioned in that paragraph: when the central bank transfers money to the government treasury to pay for debts.

Money was already printed by the previous regime.

The rollover wasn't final. As stated in the first part, the low rollover was expected and, has stated in the linked article, it will be repeated by the end of the month, where it's expected to be allocated entirely.

As mentioned in the post, adding to the money transferred by the central bank are the IMF and BID funds which are refinanced debts (negotiated at lower rate than before, not higher, ence the great accomplishment). Hence no currency emission is needed.