Valmiki Ramayana Yuddha Kanda Sarga 125 Shloka 25

तेषु those, सर्वेषु all, आरूढेषु having got in, कौबेरम् Kubera's, परमासनम् supreme seat, राघवेण by Raghava, अभ्यनुज्ञातम् with his permission, विहायसम् sky, उत्पपात flew

All the Vanaras and others having got into Kubera's Pushpaka with Rama's permission, it flew into the sky.